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INTRODUCTION 


STRUCTURAL    AND    SYSTEMATIC 

BOTANY, 

AND     VEGETABLE     PHYSIOLOGY, 

BEING 

A  FIFTH  AND  REVISED  EDITION 

OF 

THE     BOTANICAL     TEXT-BOOK, 

ILLUSTHATED  WITH  OVER  THIRTEEN  HUNDRED  WOODCUTS. 


By     ASA     GRAY,    M.D., 

FISHER   PROFESSOR   OF  NATURAL  HISTORY  IN  HARVARD  UNIVERSITY. 


NEW    YORK: 

IVISON,  PHLNNEY,  &  CO.,  48  &  50  WALKER  STREET. 

CHICAGO:   S.  C.  GRIGGS  &  CO.,  39  &  41  LAKE  STREET. 

PHILADELPHIA:    SOWER,   BARNES,   &   CO.,  AND  J.   B.    LLPPINCOTT  &    CO. 

BOSTON  :     BROWN,   TAGGARD,   &    CHASE.        CINCINNATI  :    MOORE,   WILSTACH,   KEYS,   &   CO. 

SAVANNAH  :    J.   M.   COOPER  &  CO.       NEW  ORLEANS  :     BLOOMFIELD,    STEEL,   &    CO. 

ST.   LOUIS  :    KEITH  &  WOODS.       DETROIT  :    F.   RAYMOND   &   CO. 

1860. 


Entered  according  to  Act  of  Congress,  in  the  year  1857,  by 

IVISON    AND    PHINNEY. 

in  the  Clerk's  Office  of  the  District  Court  for  the  Southern  District  of  New  York. 


University  Press,  Cambridge : 
Electrotyped  and  Printed  by  Welch,  Bigelow,  &  Co. 


PREFACE. 


This  compendious  treatise  is  designed  to  furnish  classes 
in  the  higher  seminaries  of  learning,  colleges,  and  medi- 
cal schools,  as  well  as  private  students  generally,  with  a 
suitable  text-book  of  Structural  and  Physiological  Botany, 
and  a  convenient  introduction  to  Systematic  or  Descriptive 
Botany,  adapted  to  the  present  condition  of  the  science. 
The  favor  with  which  the  former  editions  have  been  re- 
ceived, while  it  has  satisfied  the  author  that  the  plan  of  the 
work  is  well  adapted  to  the  end  in  view,  has  made  him  the 
more  desirous  to  improve  its  execution,  and  to  render  it  a 
better  exponent  of  the  present  state  of  Botany.  In  this 
view,  the  structural  and  physiological  part  of  the  work,  and 
the  chapters  on  the  Principles  of  Classification  and  of  the 
Natural  System,  have  been  again  almost  entirely  rewritten, 
and  such  changes  made  as  the  advanced  state  of  our  knowl- 
edge required,  or  the  author's  continued  experience  in 
teaching  has  suggested.  This  has  been  done  without  in- 
creasing the  extent  of  this  part  of  the  volume,  which,  con- 
sidering the  limited  time  devoted  to  the  study  in  our  col- 
leges, &c,  is  found  to  be  as  full  as  is  desirable  for  a  text- 
book. Being  intended  as  a  manual  for  instruction  merely, 
the  Illustrations  of  the  Natural  Orders,  which  form  the  prin- 
cipal portion  of  the  systematic  part  of  the  work,  are  brief 


IV  PREFACE. 

and  general.  Such  a  sketch,  however  amplified,  could  never 
take  the  place  of  a  Flora,  or  System  of  Plants,  hut  is  de- 
signed merely  to  give  a  general  idea  of  the  distribution  of 
the  vegetable  kingdom  into  families,  &c,  with  a  cursory  no- 
tice of  their  structure,  properties,  and  principal  useful  pro- 
ducts. In  applying  the  principles  of  classification,  and  his 
knowledge  of  the  structure  of  plants,  to  the  investigation  of 
the  plants  that  grow  spontaneously  around  him,  the  student 
will  necessarily  use  some  local  Flora,  such,  for  example,  as 
the  author's  Manual  of  the  Botany  of  the  Northern  United 
States.  For  particular  illustrations  the  botanist  may  ad- 
vantageously consult  the  author's  Genera  of  the  Plants  of 
the  United  States  illustrated  by  Figures  and  Analyses  from 
Nature,  of  which  two  volumes  have  been  published. 

About  twenty-four  of  the  wood-cuts  are,  by  permission, 
selected  from  original  sketches  made  for  a  Report  on  the 
Trees  of  the  United  States,  in  preparation  by  the  author  for 
the  Smithsonian  Institution.  The  numerous  figures  added 
to  this  edition  are  wholly  of  an  original  character. 

The  numerals  enclosed  in  parentheses,  which  abound  in 
the  pages  of  this  work,  are  references  to  other  and  mostly 
earlier  paragraphs,  in  which  the  subjects  or  the  terms  in 
question  are  treated  of  or  explained. 

A  full  Glossary  or  Dictionary  of  Botanical  Terms  (com- 
bined with  an  Index)  is  added  to  the  volume.  In  this,  it 
is  thought,  the  student  will  find  explanations  of  all  the 
technical  botanical  terms  he  is  likely  to  meet  with  in  descrip- 
tive works,  written  in  the  English  language.  The  words 
are  here  accentuated,  in  all  cases  where  this  seemed  to  be 
needful. 

Harvard  University,  Cambridge,  Sept.  1857. 


CO  X  TENTS, 


Page 

INTRODUCTION.  — General  View  of  the  Science    .        .13 


PART   I. 
STRUCTURAL  AND  PHYSIOLOGICAL  BOTANY. 

CHAPTER  I.  — OF  THE  ELEMENTARY   STRUCTURE   OF 

PLANTS 17 

Sect.  I.     Of  Organization  in  General     .        .        .        .17 

The  Elementary  Constitution  of  Plants  .  .  .  .  17 
Their  Organic  Constitution  .  .  .  .  •  .  .18 
Distinctions  between  Minerals  and  Organized  Beings  1 9 

Individuals  and  Species 20 

Life 21 

Difference  between  Vegetables  and  Animals  .        .         .21 

Sect.  n.     Of  the  Cells  and  Cellular  Tissue  of  Plants   22 

Cellular  Structure 23 

The  Cell  as  a  Living  Organism       ......     2G 

Its  Formation  and  Growth          .         .         .         .         .         .  27 

Original  Cell-Formation         .         .         .         .         •         .  .27 

Cell-Multiplication 2S 

Free  Cell-Multiplication  within  a  Mother-Cell          .         .  .30 

Cell-Growth 30 

Branching  Cells     .         .         .         .         .         .         .         .  .31 

Cyclosis  or  Circulation  in  Cells  .         .         •         .         .         .  31 
1* 


Yl  CONTENTS. 

Transference  of  Fluid  from  Cell  to  Cell          ....  33 

Increase  of  Cell- Walls  in  Thickness 34 

Markings  of  the  Walls  of  Cells 36 

Dots  or  Pits 37 

Disks  of  Coniferous  Wood      .         .         .         .         .         .         .38 

Bands,  Kings,  or  Spiral  Markings       .....  39 

Gelatinous  Coils 40 

Sect.  III.    Of  the  Kinds  or  Transformations  of  Cellu- 
lar Tissue,  viz.  Woody  Tissue,  Ducts,  etc.     40 

Parenchyma       .........  41 

Prosenchyma,  Woody  Tissue 41 

Bast  Tissue         .........  44 

Vascular  Tissue  or  Vessels,  Dotted  Ducts,  &l\         .         .  .45 

Interlaced  Fibrilliform  Tissue 48 

Laticiferous  Tissue           .         .         .         .         .         .         .  .49 

Intercellular  System           .......  50 

Epidermal  System           .         .         .         .         .         .         .  .51 

Sect.  IV.     Of  the  Contents  of  Cells  ...        52 

Sap,  Sugar 53 

Starch 54 

Amyloid        ..........     55 

Oils,  Wax,  Vegetable  Acids 56 

Essential  Oils,  Tannin,  Alkaloids   .         .         .         .         .         .57 

Chlorophyll         .  58 

Earthy  Incrustations       .         .         .         .         .         .         .         .58 

Crystals  or  Raphides,  Cystolithes 59 

CHAPTER  II.  —  OF  THE  GENERAL  DEVELOPMENT  AND 

MORPHOLOGY   OF  PLANTS 60 

Sect.  I.  Plants  of  the  Lower  Grade;  their  Develop- 
ment from  the  Cell    .         .         .         .         .         61 

Plants  of  a  Single  Cell 61 

Plants  of  a  Single  Row  of  Cells 65 

Plants  of  a  Single  Plane  or  Layer  of  Cells      .         .         .  .66 

Plants  of  a  Solid  Tissue  of  Cells         .         .         .          .         .  67 

Plants  with  a  Distinct  Axis  and  Foliage           .         .         .  .67 

Cellular  and  Vascular  Plants     ......  68 

Flowerless  or  Cryptogamous  Plants       .         .         .         .  .69 


CONTENTS.  Vll 

Sect.  II.   Plants  of  the  Higher  Grade;  their  Develop- 
ment from  the  Seed  .....  69 

Flowering  or  Phamogamous  Plants       .         .         .         .         .60 
Organs  of  Vegetation  and  of  Reproduction        ...  70 

The  Seed 70 

The  Development  of  the  Embryo  in  Germination      .  .  71 

Number  of  Cotyledons         .......       78 


CHAPTER  III.  —  OF  THE  ROOT,  OR  DESCENDING  AXIS  71) 

Absorption  by  Roots ;  their  Growth  .....  80 

Primary  and  Secondary  Roots      ......  83 

Annuals,  Biennials   ........  83 

Perennials           .........  84 

Aerial  Roots  .........  85 

Epiphytes,  or  Air-Plants       .         .         .         .         .         .         .87 

Parasites 88 


CHAPTER  IV.  — OF  THE  STEM,  OR  ASCENDING  AXIS      91 

Sect.  I.    Its   General   Characteristics   and  Mode   of 

Growth         .         .        .  .        .        .  91 

Nodes  and  Intern  odes  .         . 92 

Buds 93 

Plan  of  Vegetation      .  95 

Phytons 96 

Sect.  II.   Ramification 97 

Branches 97 

Adventitious  and  Accessory  Buds         .....       98 

Excurrent  and  Deliquescent  Stems  .         .         .         .         .  99 

Definite  and  Indefinite  Growth    .         .         .         .         .         .100 

Propagation  from  Buds     .         .         .         .         .         .         .         100 

Sect.  HI.    The  Kinds  of  Stem  and  Branches  .        .     101 

Herbs,  Shrubs,  Trees,  &c. 101 

Stolons,  Suckers,  Runners    .         .         .         .         .         .  .102 

Offsets,  Tendrils 103 

Spines  or  Thorns           .         .         .         .         .         .         .  .104 

Subterranean  Modifications 105 


Vlll  CONTENTS. 

Rhizoma  or  Rootstock 106 

Tuber 107 

Corm 108 

Bulbs  and  Bulblets 109 

Consolidated  Forms  of  Vegetation 110 

Sect.  IV.   The  Internal  Structure  of  the  Stem        .  Ill 

Sect.  V.    The  Endogenous  or  Monocotyledonous  Stem  114 

Sect.  VI.   The  Exogenous  or  Dicotyledonous  Stem  116 

The  First  Year's  Growth 118 

The  Wood 119 

The  Bark 120 

The  Cambium-Layer 122 

Annual  Increase  of  the  Wood 123 

Sap-wood  and  Heart-wood 124 

The  Bark ;  its  particular  Structure       .         .         .         .         .126 

The  Living  Parts  of  a  Tree,  &c 129 

The  Plant  a  Composite  Being,  Individuality  .         .         .131 

Comparison  of  Endogenous  with  Exogenous  Structure      .  132 

CHAPTER  V.  — OF  THE  LEAVES 133 

Sect.  I.   Their   Arrangement 133 

Phyllotaxis 133 

Vernation  or  Praefoliation 143 

Sect.  H.   Their  Structure  and  Conformation      .        .  145 

Anatomy  of  the  Leaf 145 

Stomata 150 

Development  of  Leaves 153 

The  Venation  and  Forms  of  Leaves 154 

Compound  Leaves 163 

Leaves  of  Peculiar  Conformation  or  Transformation      .         .165 

The  Petiole  or  Leafstalk,  Phyllodia,  Stipules     .         .        .  1 70 

Sect.  IH.  The  Duration  of  Leaves;  their  Action,  etc.  172 

Fall  of  the  Leaf 173 

Death  of  the  Leaf 1 74 

Exhalation  from  the  Leaves,  Rise  of  the  Sap    .         .         .  175 


CONTENTS.  IX 

CHAPTER  VI  —  OF  THE  FOOD   AND  NUTRITION   OF 

PLANTS 177 

Sect.  I.   The  General  Physiology  of  Vegetation     .  177 

Sect.  II.   The  Food  and  the  Elementary  Composition 

of  Plants 179 

The  Organic  Constituents       .         .         .         .         .         .  180 

The  Inorganic  or  Earthy  Constituents         ....  186 

Sect.  IH.   Assimilation,  or  Vegetable  Digestion,  and 

its  Results 190 

Process  and  Results  of  Assimilation      .         .         .         .         .191 

Effect  on  the  Atmosphere 199 

Relations  of  the  Vegetable  to  the  Animal  and  Mineral  King- 
doms         201 

CHAPTER  VII.  —  OF  FLOWERING 204 

Flowering  an  Exhaustive  Process 204 

Evolution  of  Heat            .......  206 

Plants  need  a  Season  of  Rest      ......  207 

CHAPTER  VHL—  OF   THE  INFLORESCENCE      .        .  209 

Indefinite  or  Indeterminate  Inflorescence     .         .        .         .210 

Definite  or  Determinate  Inflorescence      .         .         .         .  217 

CHAPTER  IX.  — OF   THE  FLOWER 221 

Sect.  I.  Its  Organs,  or  Component  Parts   ...  221 

Sect.  II.  Its  Theoretical  Structure  or  Morphology  224 

Sect.  in.  Its  Symmetry 232 

Alternation  of  the  Floral  Organs 235 

Position  as  Respects  the  Axis  and  Bract  .         .         .         .  237 

Sect.  IV.  The  Various  Modifications  of  the  Flower  238 

Augmentation  of  the  Floral  Circles 242 

Chorisis  or  Deduplication 243 


X  CONTENTS. 

Anteposition  or  Superposition  ......  248 

Coalescence  of  Parts     ........  249 

Adnation  or  Consolidation         ......  250 

Irregularity          .........  253 

Suppression  or  Abortion           ......  255 

Unusual  States  of  the  Receptacle         .....  266 

The  Disk 267 

Sect.  V.   The  Floral  Envelopes  in  Particular     .        .  268 

Their  Development  or  Organogeny          ....  268 

Their  Estivation  or  Prajfloration 269 

The  Calyx 274 

The  Corolla 275 

Sect.  VI.   The  Stamens 279 

The  Filament  and  Anther  .         .  .         .         .         .         .281 

The  Pollen 285 

Sect.  VII.   The  Pistils 287 

The  Simple  Pistil 288 

The  Placenta 289 

The  Compound  Pistil 290 

Modes  of  Placentation 292 

Gynsecium  of  Gymnospermous  Plants        ....  296 

Sect.  VTTI.    TnE  Ovule 297 

Sect.  IX.  Fertilization  and  Formation  of  the  Embryo  300 

Parthenogenesis 300 

Access  of  the  Pollen    ........  301 

Action  of  the  Pollen  on  the  Stigma 302 

Origin  of  the  Embryo 304 

CHAPTER  X.  —  OF  THE  FRUIT 308 

Sect.  I.   Its  Structure,  Transformations,  &c.       .        .  308 

The  Pericarp  or  Seed-vessel     .         .         .         .         .         .  308 

Obliteration  or  Alteration 309 

Ripening,  Dehiscence 310 

Sect.  II.   Its  Kinds 311 


CONTENTS.  XI 

CHAPTER  XI.  — OF   THE   SEED 320 

Sect.  I.  Its  Structure  and  Parts 320 

The  Nucleus  and  Albumen       .         .         .         .         .         .         322 

The  Embryo       .         .         .         .         .         .         .         .         .323 

Sect.  II.    Germination 328 

CHAPTER     XII.  —  OF    REPRODUCTION    IN     CRYPTO- 

GAMOUS    OR  FLOWERLESS  PLANTS        .         .     330 

CHAPTER  XIII.  —  OF  THE  SPONTANEOUS  MOVEMENTS 

AND  VITALITY   OF  PLANTS    ....        340 

Special  Directions 341 

Sensible  Movements  from  Irritation  ....         345 

Spontaneous  or  Automatic  Movements  .  .  .  .347 
Free  Movements  of  the  Spores  of  Algse  ....  348 
Locomotion  of  Adult  Microscopic  Plants       ....     349 


PART     II. 

SYSTEMATIC  BOTANY. 

CHAPTER    I  — OF  THE   PRINCIPLES   OF  CLASSIFICA- 
TION.       .         .         ; 352 

Individuals  ..........  352 

Species 354 

Varieties,  Races,  Hybrids  or  Cross-breeds     ....  355 

Genera 353 

Orders  or  Families,  Classes,  &c 359 

Characters        ••.......  362 

Binomial  Nomenclature 363 

Natural  and  Artificial  Systems 365 


CHAPTER  II.  — OF  THE  NATURAL  SYSTEM  OF  BOT- 
ANY       366 

Sketch  of  the  Classes,  &c 369 

Nomenclature  of  Orders,  Tribes,  &c 373 


Xli  CONTENTS. 

CHAPTER  III.  — ILLUSTRATIONS    OF    THE  NATURAL 

ORDERS   OR  FAMILIES 373 

CHAPTER    IV. —  OF     THE    ARTIFICIAL    SYSTEM    OF 

LINNJEUS 511 

APPENDIX. 

Signs  and  Abbreviations 517 

Directions  for  Collecting  and  Preserving  Plants,  &c.   518 

GLOSSARY  OF  BOTANICAL  TERMS  AND  INDEX    .  521 


THE 


BOTANICAL    TEXT-BOOK 


INTRODUCTION. 

GENERAL   VIEW   OF   THE   SCIENCE. 

1.  Botany  is  the  Natural  History  of  the  Vegetable  Kingdom. 
The  vegetable  kingdom  consists  of  those  beings  (called  Plants) 
which  derive  their  sustenance  from  the  mineral  kingdom,  that  is, 
from  the  earth  and  air,  and  create  the  food  upon  which  animals 
live.  The  proof  of  this  proposition  will  be  hereafter  afforded,  in 
the  chapter  upon  the  Food  and  Nutrition  of  Plants.  The  vegetable 
kingdom,  therefore,  occupies  a  position  between  the  mineral  and 
the  animal  kingdoms.  Comprehensively  considered,  Botany  accord- 
ingly embraces  every  scientific  inquiry  that  can  be  made  respect- 
ing plants,  —  their  nature,  their  kinds,  the  laws  which  govern 
them,  and  the  part  they  play  in  the  general  economy  of  the  world, 
—  their  relations  both  to  the  lifeless  mineral  kingdom  below  them, 
from  which  they  draw  their  sustenance,  and  to  the  animal  kingdom 
above  them,  endowed  with  higher  vitality,  to  which  in  turn  they 
render  what  they  have  thus  derived. 

2.  There  are  three  aspects  under  which  the  vegetable  world  may 
be  contemplated,  and  from  which  the  various  departments  of  the 
science  naturally  arise.  Plants  may  be  considered  either  as  indi- 
vidual beings ;  or  in  their  relations  to  each  other,  as  collectively 
constituting  a  systematic  unity,  that  is,  a  vegetable  kingdom ;  or  in 
their  relations  to  other  parts  of  the  creation,  —  to  the  earth,  to 
animals,  to  man. 

3.  Under  the  first  aspect,  namely,  when  our  attention  is  directed 
to  the  plant  as  an  individual,  Ave  study  its  nature  and  structure,  the 

2 


14  INTRODUCTION. 

kind  of  life  with  which  it  is  endowed,  the  organization  through 
which  its  life  is  manifested ;  —  in  other  words,  how  the  plant  lives 
and  grows,  and  fulfils  its  destined  offices.  This  is  the  province  of 
PHYSIOLOGICAL  BOTANY.  This  department  of  the  science 
naturally  divides  into  two  branches,  namely,  Structural  Botany  and 
Vegetable  Physiology,  which  arise  from  the  different  views  we  may 
take  of  plants.  The  study  of  their  organization  belongs  to  Struc- 
tural Botany,  which  includes  every  inquiry  respecting  their 
structure  and  parts.  And  this  may  again  be  divided  into  two 
branches,  viz.:  —  1st,  Vegetable  Anatomy,  or  Phytotomy,  the 
study  of  the  minute  structure  of  vegetables  as  revealed  by  the 
microscope ;  and  2d,  Organography,  the  study  of  the  organs  or 
conspicuous  parts  of  plants,  as  to  their  external  conformation ;  in- 
cluding Morphology  (the  study  of  forms),  which  relates  to  the 
conformation  and  the  symmetrical  arrangement  of  these  organs, 
and  the  modifications  they  undergo,  either  in  different  species, 
according  to  the  conditions  of  their  existence,  or  in  the  same  indi- 
vidual in  the  course  of  its  development,  —  a  department  analogous 
to  what  is  termed  Comparative  Anatomy  in  the  animal  kingdom. 
Thus  in  Structural  Botany,  whether  Ave  regard  the  external  con- 
formation or  the  minute  internal  structure,  the  plant  is  viewed  as 
a  piece  of  machinery,  adapted  to  the  accomplishment  of  certain 
ends.  On  the  other  hand,  the  study  of  this  apparatus  in  action, 
endowed  with  life,  and  fulfilling  the  purposes  for  which  it  was  in- 
tended, and  also  of  the  forces  which  operate  in  it  and  by  it,  is  the 
province  of  Vegetable  Physiology. 

4.  The  subjects  which  Physiological  Botany  embraces,  namely, 
Vegetable  Anatomy,  Organography,  and  Physiology,  therefore, 
spring  naturally  from  the  study  of  vegetables  as  individuals, — 
from  the  contemplation  of  an  isolated  plant  throughout  the  course 
of  its  existence,  from  germination  to  the  flowering  state,  and  the 
production  of  a  seed  like  that  from  which  the  parent  stock  origi- 
nated. These  branches  would  equally  exist,  and  would  form  a 
highly  interesting  study  (analogous  to  human  anatomy  and  physi- 
ology), even  if  the  vegetable  kingdom  were  restricted  to  a  single 
species. 

5.  But  the  science  assumes  an  immeasurably  broader  interest  and 
more  diversified  attractions,  when  we  look  upon  the  vegetable  crea- 
tion as  consisting,  not  of  wearisome  repetitions  of  one  particular  form, 
in  itself  however  perfect  or  beautiful,  but  as  composed  of  thousands 


INTRODUCTION.  15 

of  species,  all  constructed  upon  one  general  plan,  indeed,  but  this 
plan  modified  in  each  according  to  the  rank  it  holds,  and  the  cir- 
cumstances in  which  it  is  placed.  This  leads  to  the  second  great 
department  of  the  science,  namely,  SYSTEMATIC  BOTANY,  or 
the  study  of  plants  in  their  relations  to  one  another ;  as  forming  a 
vegetable  kingdom,  which  embraces  an  immense  number  of  species, 
resembling  each  other  in  very  various  degrees,  and  therefore  capable 
of  being  grouped  into  hinds  or  genera,  into  orders,  classes,  &c. 

6.  Thus  arises  Classification,  or  the  arrangement  of  plants  in 
systematic  order,  so  as  to  show  their  relationships  ;  also  Special 
Descriptive  Botany,  embracing  a  scientific  account  of  all  known 
plants,  designated  by  proper  names,  and  distinguished  by  clear  and 
exact  descriptions.  Necessarily  connected  with  these  departments 
is  Terminology  or  Glossology,  which  relates  to  the  application 
of  distinctive  names  or  terms  to  the  several  organs  of  plants,  and 
to  their  numberless  modifications  of  form,  &c.  The  accomplishment 
of  this  object  renders  necessary  a  copious  vocabulary  of  technical 
terms  ;  for  the  current  words  of  ordinary  language  are  not  suf- 
ficiently numerous  or  precise  for  this  purpose.  New  terms  are 
therefore  introduced,  for  accurately  expressing  the  great  variety 
of  new  ideas  to  which  the  exact  comparison  of  plants  gives  rise ; 
and  thus  a  technical  language  has  gradually  been  formed  (in  this 
as  in  every  other  science),  by  which  the  botanist  is  able  to  describe 
the  objects  of  his  study  with  a  clearness  and  brevity  not  otherwise 
attainable. 

7.  These  several  departments  include  the  whole  natural  history 
of  the  vegetable  kingdom,  considered  independently.  But,  under 
a  third  point  of  view,  plants  may  be  contemplated  in  respect  to  their 
relations  to  other  parts  of  the  creation ;  whence  arises  a  series  of 
interesting  inquiries,  which  variously  connect  the  science  of  Botany 
with  Chemistry,  Geology,  Physical  Geography,  &c.  Thus,  the  re- 
lations of  vegetables  with  the  mineral  kingdom,  considered  as  to 
their  influence  upon  the  soil  and  the  air,  —  as  to  what  vegetation 
draws  from  the  soil  and  what  it  imparts  to  it,  what  it  takes  from 
and  what  it  renders  to  the  air  Ave  breathe ;  and,  again,  the  relations 
of  the  vegetable  to  the  animal  kingdom,  considered  as  furnishing 
sustenance  to  the  latter,  and  the  mutual  subservience  of  plants  and 
animals  in  the  general  economy  of  the  world,  —  all  these  inquiries 
belong  partly  to  Chemistry  and  partly  to  Vegetable  Physiology; 
while   the   practical   deductions  from   them   lay  the  foundation  of 


16  INTRODUCTION. 

scientific  Agriculture,  &c.  The  relations  of  plants  to  the  earth, 
considered  in  reference  to  their  natural  distribution  over  its  surface 
and  the  laws  that  regulate  that  distribution,  especially  as  connected 
with  climate,  give  rise  to  Geographical  Botany,  a  subject  which 
connects  Botany  with  Physical  Geography.  Under  the  same  gen- 
eral department  naturally  falls  the  consideration  of  the  changes 
which  the  vegetable  kingdom  has  undergone  in  times  anterior  to 
the  present  state  of  things,  as  studied  in  the  fossil  remains  of  plants, 
(a  contribution  which  Botany  offers  to  Geology,)  as  well  as  of  those 
changes  which  man  has  effected  in  the  natural  distribution  of 
plants,  and  the  alterations  in  their  properties  or  products  which 
have  been  developed  by  culture. 

8.  Of  these  three  great  departments  of  the  science,  that  of 
Physiological  Botany,  forming  as  it  does  the  basis  of  all  the  rest, 
first  demands  the  student's  attention. 


PART   I. 
STRUCTURAL  AND  PHYSIOLOGICAL  BOTANY. 


9.  Tite  principal  subjects  which  belong  to  this  department  of 
Botany  may  be  considered  in  the  most  simple  and  natural  order 
by  tracing,  as  it  were,  the  biography  of  the  vegetable  through  the 
successive  stages  of  its  existence,  —  the  development  of  its  essen- 
tial organs,  root,  stem,  and  foliage,  the  various  forms  they  assume, 
the  offices  they  severally  perform,  and  their  combined  action  in 
carrying  on  the  processes  of  vegetable  life  and  growth.  Then  the 
ultimate  development  of  the  plant  in  flowering  and  fructification 
may  be  contemplated,  —  the  structure  and  office  of  the  flower,  of 
the  fruit,  the  seed,  and  the  embryo  plant  it  contains,  which,  after 
remaining  dormant  for  a  time,  at  length  in  germination  develops 
into  a  plant  like  the  parent ;  thus  completing  the  cycle  of  vegetable 
life.  A  preliminary  question,  however,  presents  itself.  To  under- 
stand how  the  plant  grows  and  forms  its  various  parts,  and  to  get 
a  clear  idea  of  what  growth  is,  we  must  first  ascertain  what  plants 
are  made  of. 


CHAPTER     I . 

OF    THE     ELEMENTARY    STRUCTURE    OF    PLANTS. 

Sect.  I.     Of  Organization  in  General. 
10.  The  Elementary  Constitution  of  Plants.     In  considering  the 

materials  of  which  vegetables  are  made,  it  is  not  necessary  at  the 
outset  to  inquire  particularly  into  their  chemical  or  ultimate  com- 
position, that  which  they  have  in  common  with  the  mineral  world. 

2* 


18  THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 

As  they  derive  all  the  materials  of  their  fabric  from  the  earth  and 
air,  plants  can  possess  no  simple  element  which  these  do  not  supply. 
They  may  take  in,  to  some  extent,  almost  every  element  which  is 
thus  supplied.  Suffice  it  for  the  present  to  say,  that,  of  the  about 
sixty  simple  substances  now  recognized  by  chemists,  only  four  are 
essential  to  vegetation  and  are  necessary  constituents  of  the  vege- 
table structure.  These  are  Carbon,  Hydrogen,  Oxygen,  and  Nitro- 
gen. Besides  these,  a  few  earthy  bodies  are  regularly  found  in 
plants,  in  small  and  varying  proportions.  The  most  important  of 
them  are  Sulphur  and  Phosphorus,  which  are  thought  to  take  an 
essential  part  in  the  formation  of  certain  vegetable  products,  Potas- 
sium and  Sodium,  Calcium  and  Magnesium,  Silicon  and  Aluminum, 
Iron  and  Manganese,  Chlorine,  Iodine,  and  Bromine.  None  of  these 
elements,  however,  are  of  universal  occurrence,  nor  are  they  actual 
components  of  any  vegetable  tissue. 

11.  Tlieil'  Organic  Constitution.  Although  plants  and  animals  have 
no  peculiar  elements,  though  the  materials  from  which  their  bodies 
spring,  and  to  which  they  return,  are  common  earth  and  air,  yet  in 
them  these  elements  are  Avrought  into  something  widely  different 
from  any  form  of  lifeless  mineral  matter.  Under  the  influence  of 
the  principle  of  life,  in  connection  with  which  alone  such  phenomena 
are  manifested,  the  three  or  four  simple  constituents  effect  peculiar 
combinations,  giving  rise  to  a  feAV  organizable  elements,  as  they 
may  be  termed ;  because  of  them  the  organized  fabric  of  the  vege- 
table .or  animal  is  directly  built  up.  This  fabric  is  in  a  good  degree 
similar  in  all  living  bodies ;  the  solid  parts,  or  tissues,  in  all  assuming 
the  form  of  membranes,  arranged  so  as  to  surround  cavities,  or  form 
the  walls  of  tubes,  in  which  the  fluids  are  contained.  It  is  called 
crgiutizcd  structure,  and  the  bodies  so  composed  are  called  organized 
bodies,  because  such  fabric  consists  of  parts  co-operating  with  each 
other  as  instruments  or  organs  adapted  to  certain  ends,  and  through 
which  alone  the  living  principle,  under  Avhose  influence  the  structure 
itself  was  built  up,  is  manifested  in  the  operations  which  the  plant 
and  animal  carry  on.  There  is  in  every  organic  fabric  a  necessary 
connection  between  its  conformation  and  the  actions  it  is  destined  to 
perform.  This  is  equally  true  of  the  minute  structure,  or  tissues,  as 
revealed  by  the  microscope,  and  of  the  larger  organs  which  the  tissues 
form  in  all  plants  and  animals  of  the  higher  grades,  such  as  a  leaf, 
a  petal,  or  a  tendril,  a  hand,  an  eye,  or  a  muscle.  The  tenn  organ- 
ization formerly  referred  to  the  possession  of  organs  in  this  larger 


ORGANIZATION.  19 

sense,  that  is,  of  conspicuous  parts,  or  members.  It  is  now  applied 
as  well  to  the  intimate  structure  of  these  parts,  themselves  made  up 
of  smaller  organs  through  which  the  vital  forces  directly  act. 

12.  Distinctions  between  Minerals  and  Organized  Beings.     In  no 

sense  can  mineral  bodies  be  said  to  have  organs,  or  parts  subor- 
dinate to  a  whole,  and  together  making  up  an  individual,  or  an 
organized  structure  in  any  respect  like  that  which  has  just  been 
spoken  of,  and  is  soon  (as  regards  plants)  to  be  particularly  de- 
scribed. Without  attempting  to  contrast  mineral  or  unorganized 
with  organized  bodies  in  all  respects,  we  may  briefly  state  that  the 
latter  are  distinguished  from  the  former,  —  1.  By  parentage:  plants 
and  animals  are  always  produced  under  the  influence  of  a  living 
body  similar  to  themselves,  or  to  what  they  will  become,  in  whose 
life  the  offspring  for  a  time  participates ;  while  in  minerals  there  is 
no  relation  like  that  of  parent  and  offspring,  but  they  are  formed 
directly,  either  by  the  aggregation  of  similar  particles,  or  by  the 
union  of  unlike  elements  combined  by  chemical  affinity,  independent 
of  the  influence,  and  utterly  irrespective  of  the  previous  existence, 
of  a  similar  thing.  2.  By  their  development:  plants  and  animals 
develop  from  a  germ  or  rudiment,  and  run  through  a  course  of 
changes  to  a  state  of  maturity ;  the  mineral  exhibits  no  phases  in 
its  existence  answering  to  the  states  of  germ,  adolescence,  and 
maturity,  —  has  no  course  to  run.  3.  By  their  mode  of  growth: 
the  former  increasing  by  processes  through  which  foreign  materials 
are  taken  in,  made  to  permeate  their  interior,  and  deposited  inter- 
stitially  among  the  particles  of  the  previously  existing  substance ; 
that  is,  they  are  nourished  by  food ;  —  while  the  latter  are  not 
nourished,  nor  can  they  properly  be  said  to  gi*ow  at  all ;  if  they 
increase  in  any  way,  it  is  merely  by  juxtaposition,  and  because 
fresh  matter  happens  to  be  deposited  on  their  external  surface. 
4.  By  the  power  of  assimilation,  or  the  faculty  that  plants  and 
animals  alone  possess  of  converting  the  proper  foreign  materials 
they  receive  into  their  own  peculiar  substance.  5.  Connected 
with  assimilation,  as  a  part  of  the  function  of  nutrition,  which  can 
in  no  sense  be  predicated  of  minerals,  is  the  state  of  internal  ac- 
tivity and  unceasing  change  in  living  bodies  ;  these  constantly  under- 
going decomposition  and  recomposition,  particles  which  have  served 
their  turn  being  continually  thrown  out  of  the  system  as  new  ones 
are  brought  in.  This  is  true  both  of  plants  and  animals,  but  more 
fully  of  the  latter.     The  mineral,  on  the  contrary,  is  in  a  state  of 


20  THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 

permanent  internal  repose :  whatever  changes  it  undergoes  are 
owing  to  the  action  of  some  extraneous  force,  not  to  any  inherent 
power.  This  holds  true  even  in  respect  to  the  chemical  combina- 
tions which  occur  in  the  mineral  and  in  the  organic  kingdoms.  In 
the  former  they  are  stable ;  in  the  latter  they  are  less  so  in  pro- 
portion as  they  are  the  more  under  the  influence  of  the  vital  prin- 
ciple :  as  if  in  the  state  of  unstable  equilibrium,  a  comparatively 
slight  force  induces  retrograde  changes,  through  which  they  tend 
to  reassume  the  permanent  mineral  state.  G.  Consequently  the 
duration  of  living  beings  is  limited.  They  are  developed,  they 
reach  maturity,  they  support  themselves  for  a  time,  and  then  perish 
by  death,  sooner  or  later.  Mineral  bodies  have  no  life  to  lose,  and 
contain  no  internal  principle  of  destruction.  Once  formed,  they 
exist  until  destroyed  by  some  external  power ;  they  lie  passive 
under  the  control  of  physical  forces.  As  they  were  formed  irrespec- 
tive of  the  pre-existence  of  a  similar  body,  and  have  no  self-deter- 
mining power  while  they  exist,  so  they  have  no  power  to  determine 
the  production  of  like  bodies  in  turn.  The  organized  being  may 
perish,  indeed,  from  inherent  causes ;  but  not  until  it  has  given  rise 
to  new  individuals  like  itself,  to  take  its  place.  The  faculty  of  re- 
production is,  therefore,  an  essential  characteristic  of  organized 
beings. 

13.  Individuals.  The  mass  of  a  mineral  body  has  no  necessary 
limits ;  a  piece  of  marble,  or  even  a  crystal  of  calcareous  spar, 
may  be  mechanically  divided  into  an  indefinite  number  of  parts, 
each  one  of  which  exhibits  all  the  properties  of  the  mass.  But 
plants  and  animals  exist  as  individuals;  that  is,  as  beings,  com- 
posed of  parts  which  together  constitute  an  independent  whole,  that 
can  be  divided  only  by  mutilation.  Each  owes  its  existence  to  a 
parent,  and  produces  similar  individuals  in  its  turn.  So  each  in- 
dividual is  a  link  of  a  chain ;  and  to  this  chain  the  natural-historian 
applies  the  name  of 

14.  Species.  The  idea  of  species  is  therefore  based  upon  this  suc- 
cession of  individuals,  each  deriving  its  existence,  with  all  its  peculi- 
arities, from  a  similar  antecedent  one,  and  transmitting  its  form 
and  other  peculiarities  essentially  unchanged  from  generation  to 
generation.  By  species  we  mean  abstractly  the  type  or  original 
of  each  sort  of  plant,  or  animal,  thus  represented  by  a  perennial 
succession  of  like  individuals :  or,  concretely,  the  species  is  the  sum 
of  such  individuals. 


ORGANIZATION.  21 

15.  life.  All  these  peculiarities  of  organized,  as  contrasted  with 
inorganic  bodies,  will  be  seen  to  depend  upon  this :  that  the  former 
are  living  beings,  or  their  products.  The  great  characteristic  of 
plants  and  animals  is  life,  which  these  beings  enjoy,  but  minerals 
do  not.  Of  the  essential  nature  of  the  vitality  which  so  controls 
the  matter  it  becomes  connected  with,  and  of  the  nature  of  the 
connection  between  the  living  principle  and  the  organized  structure, 
we  are  wholly  ignorant.  We  know  nothing  of  life  except  by  the 
phenomena  it  manifests  in  organized  structures.  We  have  adverted 
only  to  some  of  the  most  universal  of  these  phenomena,  those  which 
are  common  to  every  kind  of  organized  being.  But  these  are  so 
essentially  different  from  the  manifestations  of  any  known  physical 
force,  that  we  are  compelled  to  attribute  them  to  a  special  principle. 
We  may  safely  infer,  however,  that  life  is  not  a  product,  or  result, 
of  the  organization ;  but  is  a  force  manifested  in  matter,  which  it 
controls  and  shapes  into  peculiar  forms,  —  into  an  apparatus,  in 
which  means  are  manifestly  adapted  to  ends,  and  by  which  results 
are  attained  that  are  in  no  other  way  attainable.  As  we  rise  in  the 
scale  of  organized  structure  from  plants  through  the  various  grades 
of  the  animal  creation,  the  superadded  vital  manifestations  become 
more  and  more  striking  and  peculiar.  But  the  fundamental  char- 
acteristics of  living  beings,  —  those  which  all  enjoy  in  common,  and 
which  necessarily  give  rise  to  all  the  peculiarities  above  enumer- 
ated (12),  —  are  reducible  to  two,  viz.:  —  1.  the  power  of  self- 
support,  or  assimilation,  that  of  nourishing  themselves  by  taking 
in  surrounding  mineral  matter  and  converting  it  into  their  own 
proper  substance ;  by  which  individuals  increase  in  bulk,  or  grow, 
and  maintain  their  life :  2.  the  power  of  self-division  or  reproduc- 
tion, by  which  they  increase  in  numbers  and  perpetuate  the  species.* 

16.  Difference  between  Vegetables  and  Animals.  The  distinction  be- 
tween vegetables  and  minerals  is  therefore  well  defined.  But  the 
fine  of  demarcation  between  plants  and  animals  is  by  no  means 
so  readily  drawn.  Ordinarily,  there  can  be  no  difficulty  in  dis- 
tinguishing  a   vegetable   from    an    animal.     All    the   questionable 

*  A  single  striking  illustration  may  set  both  points  in  a  strong  light.  The 
larva  of  the  flesh-fly  possesses  such  power  of  assimilation,  that  it  will  increase 
its  own  weight  two  hundred  times  in  twenty-four  hours ;  and  such  consequent 
power  of  reproduction,  that  Linna3us  perhaps  did  not  exaggerate,  when  he 
affirmed  that  "  three  flesh-flies  would  devour  the  carcass  of  a  horse  as  quickly 
as  would  a  lion." 


22  THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 

cases  occur  on  the  lower  confines  of  the  two  kingdoms,  which 
exhibit  forms  of  the  greatest  possible  simplicity  of  structure,  and 
of  a  minuteness  of  size  that  baffles  observation.  Even  here  the 
uncertainty  may  be  attributable  rather  to  the  imperfection  of 
our  knowledge,  than  to  any  confusion  of  the  essential  character- 
istics of  the  two  kinds  of  beings.  If  we  cannot  absolutely  define 
them,  or,  at  least,  cannot  always  apply  the  definition  to  the  actual 
and  certain  discrimination  of  the  lowest  plants  from  the  lowest 
animals,  Ave  may  indicate  the  special  functions  and  characters  of 
each.  The  essential  characteristics  of  vegetables  doubtless  depend 
upon  the  position  which  the  vegetable  kingdom  occupies  between 
the  mineral  and  the  animal,  and  upon  the  general  office  it  fulfils. 
Plants,  as  stated  at  the  outset  (1),  are  those  organized  beings  that 
five  directly  upon  the  mineral  kingdom,  —  upon  the  surrounding 
earth  and  air.  They  alone  convert  inorganic,  or  mineral,  into 
organic  matter ;  while  animals  originate  none,  but  draw  their  whole 
sustenance  from  the  organized  matter  which  plants  have  thus  elab- 
orated. Plants,  having  thus  the  most  intimate  relations  with  the 
mineral  world,  ai'e  generally  fixed  to  the  earth,  or  other  substance 
upon  which  they  grow,  and  the  mineral  matter  on  which  they  feed 
is  taken  directly  into  their  system  by  absorption  from  without,  and 
is  assimilated  under  the  influence  of  light  in  organs  exposed  to  the 
air ;  while  animals,  endowed  with  volition  and  capable  of  respond- 
ing promptly  to  external  impressions,  have  the  power  of  selecting 
the  food  ready  prepared  for  their  nourishment,  which  is  received 
into  an  internal  reservoir  or  stomach.  The  permanent  fabric  of 
plants  is  composed  of  only  three  elements,  Carbon,  Hydrogen,  and 
Oxygen.  The  tissue  of  animals  contains  an  additional  element, 
viz.  Nitrogen.  Plants,  as  a  necessary  result  of  assimilating  their 
inorganic  food,  decompose  carbonic  acid  and  restore  its  oxygen  to 
the  atmosphere.  Animals  in  respiration  continually  recompose  car- 
bonic acid,  at  the  expense  of  the  oxygen  of  the  atmosphere  and  the 
carbon  of  plants.  These  peculiarities  will  be  explained  and  illus- 
trated in  the  progress  of  this  work. 


Sect.  II.      Of  the  Cells  and  Cellular  Tissue  of  Plants. 

17.  The  question  recurs,  What  is  the  organized  fabric  or  tissue 
of  plants,  and  how  is  vegetable  growth  effected  ?     The  stem,  leaves, 


CELLULAR    TISSUE. 


23 


and  fruit  appear  to  ordinary  inspection  to  be  formed  of  smaller  parts, 
which  are  themselves  capable  of  division  into  still  smaller  portions. 
Of  what  are  these  composed  ? 

18.  Cellular  Structure.  To  obtain  an  answer  to  this  question,  we 
examine,  by  the  aid  of  a  microscope,  thin  slices  or  sections  of  any 
of  these  parts,  such,  for  example,  as  the  young  rootlet  of  a  seed- 
ling plant.  A  magnified  view  of  such  a  rootlet,  as  in  Fig.  1,  pre- 
sents on  the  cross-section  the  appearance  of  a  network,  the  meshes 
of  which  divide  the  whole  space  into  more  or  less  regular  cavi- 
ties. A  part  of  the  transverse  slice  more  highly  magnified  (Fig.  2) 
shows  the  structure  with  greater  distinctness.  A  perpendicular 
slice  (Fig.  3)  exhibits  somewhat  similar  meshes,  showing  that  the 
cavities  do  not  run  lengthwise  through  the  whole  root  without  in- 
terruption. In  Avhatever  direction  the  sections  are  made,  the  cav- 
ities are  seen  to  be  equally  circumscribed,  although  the  outlines 
may  vary  in  shape.  Hence,  we  arrive  at  the  conclusion,  that  the 
fabric,  or  tissue,  consists  of  a  multitude  of  separate  cavities,  with 

I  2  4 


closed  partitions ;  forming  a  structure  not  unlike  a  honeycomb. 
This  is  also  shown  by  the  fact,  that  the  liquid  contained  in  a  juicy 
fruit,  such  as  a  grape  or  currant,  does  not  escape  when  it  is  cut  in 
two.  The  cavities  being  called  Cells,  the  tissue  thus  constructed 
is  termed  Cellular  Tissue.  When  the  body  is  sufficiently  trans- 
lucent to  be  examined  under  the  microscope  by  transmitted  light, 
this  structure  may  usually  be  discerned  without  making  a  section. 


FIG.  1.  Portion  of  a  young  root,  magnified.  2.  A  transverse  slice  of  the  same,  more  mag- 
nified     3.  A  smaller  vertical  slice,  magnified. 

FIG.  4.  Cellular  tissue  from  the  apple,  as  seen  in  a  section.  5.  Some  of  the  detached  cells 
from  the  ripe  fruit,  magnified. 

FIG.  6.  Portion  of  a  hair  from  the  filament  of  the  Spider  Lily  (Tradescantia),  magnified  : 
a,  vestige  of  the  nucleus. 


24 


THE    ELEMENTARY    STRUCTURE    OF    PLANTS. 


aDnaoDDcr 


We  may  often  look  directly  upon  a  delicate  rootlet  (as  in  Fig.  1), 
or  the  petal  of  a  flower,  or  a  piece  of  thin  and  transparent  sea-weed, 
and  observe  the  closed  cavities,  entirely  circumscribed  by  nearly 
transparent  membranous  walls. 

19.  Does  this  cellular  tissue  consist  of  an  originally  homogeneous 
mass,  filled  in  some  way  with  innumerable  cavities  ?  Or  is  it  com- 
posed of  an  aggregation  of  little  blad- 
ders, or  sacs,  which  by  their  accumu- 
lation and  mutual  cohesion  make  up 
the  root  or  other  organ?  Several  cir- 
cumstances prove  that  the  latter  is  the 
correct  view.  1.  The  partition  between 
two  adjacent  cells  is  often  seen  to  be 
double ;  showing  that  each  cavity  is 
bounded  by  its  own  special  walls. 
2.   There  are  vacant   spaces  often  to 

be  seen  between  contiguous  cells,  where  the  walls  do  not  entirely 
fit  together.  These  intercellular  spaces  are  sometimes  so  large 
and  numerous,  that  many  of  the  cells  touch  each  other  at  a  few 
points  only;  as  in  the  green  pulp  of  leaves  (Fig.  7).  3.  When 
a  portion  of  any  young  and  tender  vegetable  tissue,  such  as  an 
Asparagus  shoot,  is  boiled,  the  elementary  cells  separate,  or  may 
readily  be  separated  by  the  aid  of  fine  needles,  and  examined  by 
the  microscope.  4.  In  pulpy  fruits,  as  in  the  apple,  the  walls  of 
the  cells,  which  at  first  cohere  together,  spontaneously  separate  as 
the  fruit  ripens  (Fig.  4,  5). 

20.  The  vegetable,  then,  is  constructed  of  these  cells  or  vesicles, 
much  as  a  wall  is  built  up  of  bricks.     When  the  cells  are  separate, 

or  do  not  impress  each  other,  they  are  generally  round- 
ed or  spherical.  By  mutual  pressure  they  become 
Y\\  many-sided.  In  a  mass  of  spheres  each  one  is  touched 
by  twelve  others;  so  if  equally  impressed  in  every 
direction,  the  yielding  cells,  flattening  each  other  at  the 
points  of  contact,  become  twelve-sided ;  and  in  a  section, 
whether  transverse  (as  in  Fig.  2)  or  longitudinal  (as  in 

FIG.  7.  A  magnified  section  through  the  thickness  of  a  leaf  of  Illicium  Floridanum,  show- 
ing the  irregular  spaces  or  passages  between  the  cells,  which  are  small  in  the  upper  layer  of 
the  green  pulp,  the  cells  of  which  (placed  vertically)  are  well  compacted,  so  as  to  leave  only 
minute  vacuities  at  their  rounded  ends ;  but  the  spaces  are  large  and  copious  in  the  rest  of 
the  leaf,  where  the  cells  are  very  loosely  arranged,  o,  The  epidermis  or  skin  of  the  upper, 
b,  of  the  lower  surface  of  the  leaf,  composed  of  perfectly  combined  and  thick-walled  cells. 

FIG.  8.     View  of  a  twelve-sided  cell,  detached  entire,  from  tissue  like  that  of  Fig.  9. 


CELLULAR    TISSUE. 


25 


Fig.  3),  the  meshes  consequently  appear  six-sided.  If  the  organ 
is  growing  in  one  direction  more  than  another,  the  cells  commonly 
lengthen  more  or  less  in  that 
direction.  It  is  not  necessary  to  _-^ 
■  detach  a  cell  in  order  to  ascertain  ^S 
its  shape ;  that  may  usually  be 
inferred  from  the  outlines  of  the    |J| 

i  t  •  1 1 1  t! 

section  m  two  or  three  directions. 

21.  The  shape  of  cells,  there- 
fore, when  they  compose  a  tissue, 
depends  Arery  much  upon  the  way 
in  which  they  are  arranged  and 
press  upon  each  other.  "When 
separate,  as  they  are  in  the  sim-  '7i 
plest  vegetables,  or  when  nearly 
free  from  each  other,  like  the  hairs  on  the  surface  of  many  plants, 
they  determine  their  own  form  by  their  mode  of  growth,  and  assume 
a  great  variety  of  shapes,  some  of  which  are  shown  in  the  follow- 
ing illustrations.  The  natural  and  primitive  form  may  be  said  to 
be  roundish  or  spherical.  By  increased  growth  in  one  direction 
they  become  oblong  or  cylindrical,  or,  when  still  more  extended, 
they  become  tubes.  Of  this  kind  are  the  hair-like  prolongations 
on  the  surface  of  young  rootlets  (shown  just  beginning  in  Fig.  1, 
and  more  elongated  in  Fig.  135  —  137);  and  the  fibres  of  cotton 
are  slender  hairs,  consisting  of  single,  very  long  cells,  growing  on 
the  surface  of  the  seed. 

22.  The  Avails  of  young  cells  are  transparent  and  colorless.  The 
various  colors  which  the  parts  of  the  plant  present,  the  green  of 
the  foliage,  and  the  vivid  hues  of  the  corolla,  do  not  belong  to  the 
tissues  themselves,  but  to  the  matters  of  different  colors  which  the 
cells  contain  (92).  As  they  become  older,  the  walls  often  lose  most 
of  their  transparency,  and  even  acquire  peculiar  colors,  as  in  the 
heart-wood  of  various  trees. 

23.  The  cells  vary  greatly  in  size,  not  only  in  different  plants, 
but  in  different  parts  of  the  same  plant.  The  largest  are  found  in 
aquatics,  and  in  such  plants  as  the  Gourd,  where  some  of  them  are 
as  much  as  one  thirtieth  of  an  inch  in  diameter.  Their  ordinary 
diameter  in  vegetable  tissue  is  between  %£v  and  Tv!ijiy  °f  an  mcn- 

PIG.  9.    A  small  portion  of  the  tissue  of  pith,  seen  both  in  transverse  and  longitudinal 
section,  much  magnified. 

3 


26  THE    ELEMENTARY    STRUCTURE    OF    PLANTS. 

The  smaller  of  these  sizes  would  allow  of  as  many  as  1728  millions 
of  cells  in  the  compass  of  a  cubic  inch ! 

24.  Some  idea  may  be  formed  respecting  the  rate  of  their  pro- 
duction, by  comparing  their  average  size  in  a  given  case  with  the 
known  amount  of  growth.  Upon  a  fine  day  in  the  spring,  many 
stems  shoot  up  at  the  rate  of  three  or  four  inches  in  twenty-four 
hours.  "When  the  Agave  or  Century-plant  blooms  in  our  conser- 
vatories, its  flower-stalk  often  grows  at  the  rate  of  a  foot  a  day ;  it 
is  even  said  to  grow  with  twice  that  rapidity  in  the  sultry  climate  to 
which  it  is  indigenous.  In  such  cases,  new  cells  must  be  formed  at 
the  rate  of  several  millions  a  day.  The  rapid  growth  of  Mushrooms 
has  become  proverbial.  A  gigantic  species  of  Puff-ball  has  been 
known  to  attain  the  size  of  a  large  gourd  during  a  single  night : 
in  this  case  the  cells  of  which  it  is  composed  are  computed  to  have 
been  developed  at  the  rate  of  three  or  four  hundred  millions  per 
hour.  But  this  rapid  increase  in  size  is  owing,  in  great  part,  to  the 
expansion  of  cells  already  formed. 

25.  The  Cell  as  a  living  Organism.  Thus  far  we  have  considered 
only  the  membrane  or  permanent  wall  of  the  cell,  —  that  which 
makes  up  the  tissue  or  fabric  of  plants,  and  which  remains  un- 
altered, and  performs  some  of  its  offices  even  long  after  life  has 
departed.  But  we  should  now  regard  the  cell  as  a  living  thing, 
and  consider  what  the  Avail  encloses,  and  what  operations  are 
effected  in  it.  For  the  Avhole  life  of  the  plant  is  that  of  the  cells 
which  compose  it ;  in  them  and  by  them  its  products  are  elaborated, 
and  all  its  vital  processes  carried  on. 

26.  A  3roung,  living,  vitally  active  cell  consists,  —  1st,  of  the 
membrane  or  permanent  wall,  already  described ;  2d,  of  a  delicate 
mucilaginous  film,  fining  the  wall,  called  by  Mohl  the  primordial 
utricle ;  3d,  most  commonly  the  centre  of  the  cell,  and  sometimes 
the  greater  part  of  the  cavity,  is  occupied  by  the  nucleus,  a  soft 
solid  or  gelatinous  body ;  and  4th,  the  space  between  the  nucleus 
and  the  lining  membrane  is  filled  at  first  by  a  viscid  liquid,  called 
protoplasm,  having  an  abundance  of  small  granules  floating  in  it. 
As  the  cell  enlarges  by  the  growth  and  expansion  of  its  walls,  the 
space  between  the  latter  and  the  nucleus  becomes  filled  with  watery 
sap,  leaving  the  protoplasm  merely  as  a  viscid  coating  of  the  inside 
of  the  primordial  utricle,  and  of  the  nucleus,  if  this  remains. 

27.  The  cell-membrane,  or  proper  wall  of  the  cell,  is  chemically 
composed  of  the   three   elements,  carbon,  hydrogen,  and   oxygen, 


FORMATION    AND    GROWTH    OF    CELLS.  27 

and  has  the  same  composition  (when  pure)  in  all  plants.  This  sub- 
stance —  the  general  material  of  vegetable  fabric  —  is  called  Cellu- 
lose. Its  chemical  composition  is  Carbon  12,  Hydrogen  10,  and 
Oxygen  10.  It  is  insoluble  in  water,  alcohol,  ether,  and  dilute  acids, 
and,  like  starch,  it  turns  blue  when  acted  upon  by  iodine,  aided  by 
sulphuric  acid.  The  primordial  utricle,  or  delicate  lining  of  the 
cell,  appears  to  have  the  same  composition  as  protoplasm.  It  may 
be  regarded  as  an  exterior  portion  of  the  mucilaginous  protoplasm, 
which  has  acquired  the  consistence  of  a  very  soft  membrane.  In 
addition  to  the  three  elements,  carbon,  hydrogen,  and  oxygen,  pro- 
toplasm contains  nitrogen,  in  considerable  quantity.  It  is  colored 
yellow  by  iodine,  and  is  coagulated  by  alcohol  and  acids.  The 
substance  of  which  it  principally  consists  is  named  by  chemists 
Proteine,  and  is  known  among  vegetable  products  under  various 
forms,  viz.  as  diastase,  gluten,  fibrine,  vegetable  albumen,  and  the 
like.  Such  being  the  nature  and  the  parts  of  the  cell,  we  may  now 
consider 

28.  Its  Formation  and  Growth.  Under  this  head  we  may  briefly 
explain,  as  far  as  we  are  able,  —  1st,  how  cells  are  originated;  and 
2d,  how  they  are  multiplied. 

29.  Original  Cell-Formation.  Cells  are  originated  only  within  other 
cells,  or  at  least  in  matter  which  has  been  contained  in  and  elab- 
orated by  them.  They  appear  to  be  formed  in  the  following  man- 
ner. A  portion  of  the  elaborated  or  organizable  matter,  which 
abounds  in  the  fluid  contents  of  living  cells,  condenses  into  a  soft 
solid,  or  half-solid  and  more  or  less  transparent  mass,  usually  of  a 
globular  of  oval  shape,  the  nucleus:  around  this  nucleus  a  portion  of 
protoplasm  accumulates ;  a  denser  film  of  the  same  substance  forms 
on  the  surface  of  the  protoplasm,  giving  the  mass  a  definite  outline ; 
this  is  the  primordial  utricle :  upon  this  a  layer  of  cellulose  is  soon 
deposited,  making  the  cell-membrane.  The  nuclei  in  such  cases  are 
very  minute,  and  either  few  or  many  of  them  may  be  formed  in 
one  parent  cell,  and  be  developed  in  this  way  into  new  cells,  which 
are,  at  least  at  first,  of  small  size  as  compared  with  the  parent  cell 
(Fig.  88).  A  variation  of  this  mode  occurs  in  many  of  the  lower 
Alga1,  where  a  considerable  portion  of  the  contents  of  a  cell  con- 
denses into  a  rounded  mass,  the  surface  becomes  coated  with  a 
layer  of  protoplasm  or  primordial  utricle,  and  this  with  a  membrane 
of  cellulose,  completing  the  cell.  Thus,  in  Vaucheria  the  whole 
green  contents    at   the   end  of  certain   branches    condense   into  a 


28  THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 

globular  mass  (Fig.  89),  which  at  length  is  coated  with  cell-mem- 
brane, and  so  becomes  a  cell  of  considerable  size.  In  Zygnema 
(Fig.  635)  the  whole  contents  of  two  cells  are  united,  and  give 
rise  in  a  similar  way  to  one  new  cell. 

30.  In  the  higher  or  flower-bearing  division  of  plants,  this  process 
of  original  or  free  cell-formation  occurs  only  in  the  sac  in  which  the 
embryo  is  formed.  The  first  cell  of  the  embryo  originates  in  this 
way ;  but  all  the  subsequent  growth  is  effected  by  a  different  pro- 
cess. In  the  simplest  grade  of  plants  it  occurs  more  frequently, 
but  only  in  the  formation  of  those  bodies  which  in  them  take  the 
place  and  fulfil  the  office  of  seeds ;  that  is,  which  serve  for  repro- 
duction. 

31.  It  appears,  therefore,  that  the  azotized  or  nitrogenous  mate- 
rial, the  proteine,  plays  the  most  important  part  in  the  formation 
of  cells.  The  layer  of  protoplasm,  with  its  delicate  coating,  the 
primordial  utricle,  precedes  the  proper  cell-membrane,  and  in 
some  unexplained  way  causes  the  latter  to  be  deposited  on  its  sur- 
face. And  these  soft  nitrogenous  parts  are  the  seat  of  the  whole 
vital  activity  of  the  cell.  The  wall  of  cellulose  may  be  regarded 
as  a  kind  of  protecting  coat  or  shell,  which  constitutes  the  per- 
manent fabric  of  the  plant,  but  is  alive  only  so  long  as  the  living 
protoplasmic  lining  remains. 

32.  In  a  growing  young  cell,  the  walls  enlarge  much  faster  than 
the  nucleus,  and  the  latter  soon  ceases  to  grow  at  all.  It  is  there- 
fore left  in  the  centre,  or  else  remains  adherent  to  the  Avail  on  one 
side,  where  traces  of  it  may  often  for  a  long  time  be  detected ;  or 
more  commonly  it  dissolves  and  disappears  altogether.  At  length, 
in  older  cells,  the  liquid  contents  and  the  protoplasmic  lining  also 
disappear,  and  only  the  Avails  of  cellulose  remain  as  the  permanent 
vegetable  fabric.  The  fabric  of  plants,  however,  as  has  already 
been  stated,  is  not  built  up  by  original  cell-formation,  but  by 

33.  Cell-Multiplicatioil.  A  living  cell,  formed  in  whatever  manner, 
has  the  power  of  multiplying  itself  by  dividing  into  tAvo,  these  again 
into  two  more,  and  so  on.  By  this  process  the  single  cell,  which 
each  vegetable  begins  Avith,  gives  rise  to  the  embryo  or  rudimen- 
tary plantlet  contained  in  a  seed ;  and  by  it  the  embryo  in  germina- 
tion develops  into  a  seedling,  and  the  seedling  into  the  herb,  shrub, 
or  tree.  Vegetable  groAvth  accordingly  consists,  —  1st,  of  the  groAvth 
or  expansion  of  each  cell  up  to  its  full  size,  which  ordinarily  is  veiy 
soon  attained ;  and  2d,  of  Avhat  is  called  their  mffrismatic  multiplied- 


FORMATION    AND    GROWTH    OF    CELLS. 


29 


G3 


tion,  namely,  the  successive  division  of  cells  into  two.     This  takes 

place  only  when  they  are  young  and  active,  and  mostly  before  they 

are  full-grown.     It  is  effected  by  the  formation  of  a 

partition  across  the  cavity  of  the  cell,  dividing  it  into 

two  (Fig.  10-14).     In  this  way,  a  single  cell  gives 

rise<to  a  row  of  connected  cells,  when  the  division 

takes  place  in  one  direction  only ;  or  to  a  plane  or 

solid  mass  of  such  cells,  when  it  takes  place  in  two 

or  more  directions,  thus  producing  a  tissue. 

34.  In  this  multiplication  of  cells  by  division,  as  in 
the  original  formation  of  a  cell,  the  contents  and  the 
protoplasmic  lining  play  the   most  im- 
,. '™v  portant  part.     The  nucleus,  when  pres- 

ent, as  it  commonly  is,  first  divides 
into  two  (Fig.  11)  ;  then  the  lining  mem- 
brane, or  primordial  utricle,  is  gradu- 
ally constricted  or  infolded  at  the  line 
of  division,  which,  soon  meeting  in  the 
centre,    separates    the    whole    contents  /$h 

into  two  parts  by  a  delicate  partition; 

upon   this   a  layer  of  cellulose   is   de-         /  §C1 

i  \ 
posited    as    a    permanent    Avail,    which        i  —  jL*  I 

completes    the    transformation    of   one        ***&*■-•■& 

cell  into  two  (Fig.  21,  22). 

35.  Cells  multiplying  in  this  way,  and  remaining 
united,  build  up  a  row  or  a  surface  of  cells,  or  a  solid  tissue,  ac- 
cording to  the  mode  of  division.  But  in  many  of  the  simplest 
plants,  growing  in  water,  the  cells  separate  as  they  form,  and  be- 
come independent.  A  microscopic  plant  very  common  in  shallow 
pools  in  early  spring,  forming  slimy  green  masses,  well  illustrates 
this,  as  shown  in  Figures  15-19.  At  each  step  of  this  multipli- 
cation new  cell-membranes  are  formed,  and  the  old  one,  for  instance, 
the  wall  of  Fig.  15  and  the  common  envelope  of  the  two  in  Fig.  17, 

FIG.  10.     A  young  cell,  —  the  first  cell  of  an  embryo,  —  with  its  nucleus  in  the  centre. 

11.  The  same,  with  its  nucleus  divided  into  two,  and  a  cross-partition  beginning  to  foi-m. 

12.  The  partition  completed,  so  converting  the  first  cell  into  two.  13.  The  lower  one  again 
divided  into  two,  making  three  cells  in  a  row.  14.  The  fourth  cell  converted  into  four  by  a 
division  iu  two  directions,  forming  seven  cells  in  all. 

FIG.  15.  A  single  cell,  or  plant  of  a  kind  of  Palmella,  magnified.  16.  The  same  dividing, 
and,  17,  completely  separated  into  two.  18.  Each  of  these  dividing  in  the  opposite  direc- 
tion, four  cells  are  produced.  19.  Each  of  these  again  dividing  into  four,  they  produce  a 
cluster  of  sixteen  cells. 

3* 


30 


THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 


and  of  the  four  in  Fig.  18,  forms  a  part  of  the  thickness  of  the 
coat  of  each,  or  is  destroyed  by  the  distention,  or  else  (as  in  the 
present  instance)  is  dissolved  into  a  jelly  A  slight  modification  of 
this  process  occurs  in 

36.  Free  Cell-Multiplication  within 

a  Mother-Cell,  which  is  intermediate 
in  character  between  original  cell- 
formation  and  ordinary  cell-multi- 
plication. Here  the  whole  contents 
of  a  living  cell,  by  constriction  or 
infolding  of  the  primordial  utricle, 
divide  into  two  or  four  parts  (as 
in  Fig.  81-83),  and  these  may  be 
again  divided ;  —  each  portion  has 
a  coat  of  cellulose  deposited  over 
its  surface,  and  thus  so  many  sep- 
arate cells  are  produced,  lying  loose 
in  the  cavity  of  the  mother-cell,  whose  thin  and 
now  dead  cellulose-wall,  which  is  all  that  is  left  of 
it,  usually  disappears  sooner  or  later,  or  is  broken 
up  by  the  growth  of  the  new  crop  of  cells  within. 
In  this  way  are  formed  the  grains  of  pollen  in  the 
anther,  and  the  spores,  or  bodies  which  answer  to 
seeds,  in  the  higher  grades  of  Flowerless  Plants. 

37.  Cell-Growth.  By  appropriating  assimilated 
matter,  the  young  cell  increases  in  size  until  it 
attains  its  full  growth ;  its  walls,  as  they  expand 

and  enclose  a  greater  space,  not  diminishing,  but  rather  increasing 
in  thickness.  Therefore  it  not  merely  enlarges,  but  grows.  If  it 
grows  equally  in  all  directions,  and  is  not  pressed  upon  on  any  side, 
it  keeps  a  spherical  form ;  if  it  grows  more  in  one  direction  than  in 
any  other  it  becomes  oblong  or  cylindrical.  In  this  way  a  cell  is 
sometimes  drawn  out  into  a  slender  tube ;  of  which  the  fibres  of 
cotton,  and  the  cells  of  fibrous  bark  (Fig.  49)  are  good  examples. 
In  the  simplest  plants,  cells  sometimes  continue  to  elongate  almost 

FIG  20.  The  branching  summit  of  a  plantlet  of  Conferva  glomerata,  magnified  ;  after 
Mohl.  The  plant  consists  of  a  row  of  cells,  filled  with  green  grains  floating  in  liquid  :  the 
long  cell  at  the  upper  end  is  seen  in  the  process  of  dividing  into  two,  at  a,  by  constriction  of 
the  primordial  utricle. 

FIG.  21.  A  portion  of  the  same  at  a,  more  magnified,  showing  the  formation  of  the  par- 
tition.   22.  Same,  with  the  partition  completed. 


CIRCULATION    IN    CELLS. 


31 


indefinitely  from  one  end,  by  a  sort  of  gemmation  or  budding  growth, 
while  all  the  rest  remains  stationary,  or  while  the  opposite  extremity 
is  dead  or  decaying.  Fig.  20  would  represent  a  case  of  the  kind, 
except  that  partitions  form,  as  the  upper  end  grows  on,  dividing  the 
tube  into  a  row  of  cylindrical  cells.  Sometimes  a  new  point  of 
growth  commences  on  the  side  of  a  cell,  so  giving  rise  to 

38.  Branching  Cells.  The  hair- 
like bodies  that  copiously  appear 
on  the  surface  of  young  rootlets 
furnish  examples  of  the  kind,  as 
is  shown  in  Fig.  1,  23,  24.  More 
consjiicuous  examples  are  furnish- 
ed by  certain  Algaj  of  the  simplest 
structure,  where  the  cell  branches 
profusely  as  it  elongates,  but  the 
tubes  are  all  perfectly  continu- 
ous throughout ;  as  in  Botrydium 
(Fig.  88),  where  an  originally 
spherical  cell  is  extended  and 
ramified  below  in  the  fashion  of 
a  root;   in  Vaucheria  (Fig.  89), 

where  a  slender  tube  forks  or  branches  sparingly ;  and  in  Bryopsis 
(Fig.  91),  where  numerous  branches  are  symmetrically  arranged  in 
two  opposite  rows,  like  the  plume  of  a  feather.     In  these  cases,  the 

fully  developed  plant,  with  all  its 
branches,  is  only  one  proliferous 
cell,  extended  from  various  points 
by  this  faculty  of  continuous  bud- 
ding growth.  The  mycelium  or 
spawn  of  Mushrooms,  and  the  in- 
tricate threads  of  Moulds  (Fig. 
92-94)  are  formed  of  very  attenuated  branching  cells.  And  in 
Lichens  and  many  Fungi,  cells  of  this  kind  are  densely  interwoven 
into  a  filamentous  tissue  (Fig.  25). 

39.  Cyclosis  or  Circulation  in  Cells.    In  all  young  cells,  probably, 

at  least  at  some  period,  the  fluid  protoplasm  interposed  between  the 
cell-walls  and  the  watery  sap  is  in  a  state  of  movement.     Under 

FIG.  23  Magnified  cellular  tissue  from  the  rootlet  of  a  seedling  Maple  ;  some  of  the  ex- 
ternal cells  growing  out  into  root-hairs.     24    A  few  of  the  cells  more  highly  magnified. 

FIG.  25.  Entangled,  filamentous,  branching  cells  from  the  fibrous  tissue  of  the  Reindeer 
Lichen  (Cladonia  rangiferina),  magnified. 


32 


THE    ELEMENTARY    STRUCTURE    OP    PLANTS. 


the  microscope,  currents,  rendered  more  visible  by  the  contained 
granules  or  solid  atoms,  are  seen  flowing  around  the  cell,  or  around 
some  portion  of  its  periphery,  in  a  circuit  which  returns  upon  itself 
The  cause  of  this  curious  phenomenon  and  the  object  it  subserves 
are  unknown;  but  it  is  doubtless  a  vital  circulation,  and  not  a 
mechanical  movement.  In  most  plants  it  is  not  to  be  seen  in 
mature  cells.  But  it  may  be  observed  in  many 
water-plants  when  full-grown,  and  in  the  hairs  on 
the  surface  of  a  great  variety  of  land-plants.  The 
string  of  bead-like  cells  which  compose  the  jointed 
hairs  of  the  common  Spider  Lily  (Tradescantia, 
Fig.  6)  show  this  circulation  well,  under  a  magni- 
fying power  of  about  four  hundred  diameters. 
With  this  power,  a  set  of  thread-like  currents 
may  be  seen  to  move  betAveen  the  cell-wall  and 
the  enclosed  colored  contents,  traversing  the  cell 
in  various  directions,  without  much  regularity,  ex- 
cept that  the  streamlets  appear  to  radiate  from, 
and  return  to,  the  nucleus.  The  large  stinging 
hairs  of  Nettles,  and  the  bristles  on  the  ovary  of 
Circa^a,  show  this  circulation  very  well.  In  the 
latter,  instead  of  the  separate  and  slender  stream- 
lets of  Tradescantia,  we  perceive  a  broad  and  con- 
tinuous stream  flowing  up  on  one  side  of  the  long 
cell,  around  the  summit,  and  down  the  opposite 
side.  This  circulation  may  be  more  readily  ob- 
served in  the  cells  of  many  aquatic  plants.  In 
28  Chara  and  Nitella,  —  plants   composed  of  large 

cells  lined  with  green  granules,  —  a  magnifying  power  of  fifty  or 
one  hundred  diameters  shows  the  circulation  very  well.  And  the 
leaves  of  Vallisneria  spiralis  (the  Tape-grass  or  Eel-grass  of  fresh 
water)  are  still  more  beautiful  objects,  when  magnified  from  two  to 
four  hundred  diameters.  Through  their  nearly  transparent  walls,  a 
current  of  protoplasm,  usually  carrying  with  it  some  globular  loose 
grains  of  chlorophyll,  may  be  seen  coursing  up  the  entire  breadth 
of  the  wall  of  each  cell,  across  its  summit,  down  the  opposite  side, 
and  across  the  other  end  to  complete  the  circuit ;  and  often  the 
current  is  strong  enough  to  set  the  large  nucleus,  or  a  central  mass 


FIG.  26.     A  few  cells  of  the  leaf  of  Naias  flexilis,  highly  magnified,  showing  the  circulation  ; 
the  direction  of  the  currents  indicated  by  arrow-heads.     (Drawn  by  II.  J.  Clark.) 


CIRCULATION    IX    CELLS  :    ENDOSMOSE.  33 

of  green  grains,  into  revolution.  The  circulation  is  more  active  in 
the  subjacent  than  in  the  superficial  layer  of  cells,  although  occasion- 
ally conspicuous  in  the  latter :  it  is  stopped  or  retarded  by  lower- 
ing, and  accelerated  by  raising  the  temperature.  The  motion  often 
appears  to  be  quite  rapid;  but  it  should  be  remembered  that  this  is 
magnified  as  well  as  the  object.  Mold  states  it  to  be  very  slow,  not 
more  than  the  -^^  of  a  line  per  second  in  the  hairs  of  Tradescan- 
tia.  But  in  Yallisneria  the  green  grains  sometimes  complete  the 
circuit  of  a  cell  of  the  ordinary  size  in  less  than  twenty  seconds  ; 
and  in  the  bristles  on  the  fruit  of  Circn?a,  which  are  half  a  line 
long,  Mr.  II.  J.  Clark  has  seen  the  revolution  completed  in  about  a 
minute.  The  circulation  in  one  cell  is  totally  independent  of  that 
in  the  adjacent  ones.  The  current  is  commonly  seen  to  flow  in 
opposite  directions  on  the  two  sides  of  a  partition,  or  to  move  on 
one  side  when  quiescent  on  the  other.  Cyclosis,  whatever  its 
nature  may  be,  evidently  has  nothing  to  do  with  the 

10.  Transference  of  Fluid  from  Cell  to  Cell.    All  cells,  at  least  when 

young  and  living,  have  perfectly  closed  walls.  There  is  no  passage 
from  one  to  another  through  visible  openings  or  pores,  although 
such  openings  may  be  formed  in  older  parts.  Nevertheless  fluids 
do  permeate  cell-walls,  as  they  do  all  organic  membranes.  And  in 
this  way  water,  along  with  other  matters  which  the  roots  absorb,  is 
carried  up  into  the  leaves  even  of  the  topmost  bough  of  a  tree, 
passing  in  its  course  through  many  millions  of  apparently  water- 
tight partitions.  However  governed  by  forces  inherent  in  the  plant, 
the  actual  transference  of  fluids  from  one  cell  to  another  takes  place 
in  obedience  to  a  physical  law,  i.  e.  by  the  process  which  has  been 
named  Endosmose  or  Endosmosis,*  and  which  operates  in  dead  parts 

*  Endosmose  and  exosmose  are  names  given  by  Dutrochet  (a  French  physi- 
ologist) to  a  physical  process  of  permeation  and  interchange  which  takes 
place  in  fluids,  according  to  the  following  law,  briefly  stated.  When  two 
liquids  of  unequal  density  are  separated  by  a  permeable  membrane,  the 
lighter  liquid  or  the  weaker  solution  will  flow  into  the  denser  or  stronger, 
with  a  force  proportioned  to  the  difference  in  density  (endosmosis) ;  but  at  the 
same  time,  a  smaller  portion  of  the  denser  liquid  will  flow  out  into  the  weaker 
(exosmosis).  Thus,  if  the  lower  end  of  an  open  tube,  closed  with  a  thin  mem- 
brane, such  as  a  piece  of  moistened  bladder,  be  introduced  into  a  vessel  of  pure 
water,  and  a  solution  of  sugar  in  water  be  poured  into  the  tube,  the  water  from 
the  vessel  will  shortly  be  found  to  pass  into  the  tube,  so  that  the  column  of 
liquid  it  contains  will  increase  in  height  to  an  extent  proportionate  to  the 
strength  of  the  solution.     At  the  same  time,  the  water  in  the  vessel  will  become 


34  THE    ELEMENTARY    STRUCTURE    OF    PLANTS. 

as  well  as  in  living  ones.  The  law  is,  that  when  two  fluids  of  un- 
equal density  are  separated  by  an  organic  membrane,  or  by  any  thin 
and  porous  partition,  an  interchange  takes  place,  —  more  or  less 
rapidly  according  to  the  thinness  of  the  intervening  partition  and 
the  difference  in  the  density  of  the  fluids  on  the  two  sides,  —  a  small 
quantity  of  the  denser  fluid  passing  into  the  lighter,  but  a  much  larger 
portion  of  the  lighter  passing  into  the  denser;  and  this  continues 
until  the  two  fluids  are  brought  to  the  same  density.  Hence,  as 
the  cells  of  a  living  plant  always  contain  organizable  or  assimilated 
matter  (mucilage,  protoplasm,  &c.),  which  especially  abounds  in 
young  and  growing  parts,  the  cells  of  the  rootlets  are  always  able 
to  imbibe  the  ordinary  moisture  which  is  presented  to  them  in  the 
soil ;  and  by  diminishing  the  portion  of  water,  or  in  any  other  way 
increasing  the  density  of  the  liquid  contents  of  the  cells  of  any  part 
of  the  plant,  a  flow  may  be  attracted  into  them. 

41.  Increase  of  Cell-walls  in  Thickness.    Up  to  a  certain  point,  the 

walls  of  cells  thicken  as  they  grow  by  the  incorporation  of  new 
matter  interstitially  into  their  substance.  After  attaining,  for  the 
most  part  rapidly,  a  definite  size,  the  cell  ceases  to  enlarge,  and  its 
wall  no  longer  incorporates  new  materials.  Some  cells  remain  with 
exceedingly  thin  and  delicate  walls.  But  in  most  cells  that  make 
part  of  the  permanent  structure  of  a  plant,  the  cell-membrane  con- 
tinues to  thicken  long  after  it  has  ceased  to  enlarge.  Then  the 
new  matter  can  no  longer  be  incorporated  with  the  old ;  but 
the  thickening  is  now  effected  by  its  deposition  on  the  inner  sur- 
face of  the  original  membrane,  between  it  and  the  protoplasmic 


slightly  sweet ;  showing  that  a  small  quantity  of  sirup  has  passed  through  the 
pores  of  the  membrane  into  the  water  without,  while  a  much  larger  portion  of 
water  has  entered  the  tube.  The  water  will  continue  to  enter  the  tube,  and  a 
small  portion  of  sirup  to  leave  it,  until  the  solution  is  reduced  to  the  same 
strength  as  the  liquid  without.  If  a  solution  of  gum,  salt,  or  any  other  sub- 
stance, be  employed  instead  of  sugar,  the  same  result  will  take  place.  If  the 
same  solution  be  employed  both  in  the  vessel  and  the  tube,  no  transference  or 
change  will  be  observed.  But  if  either  be  stronger  than  the  other,  a  circulation 
will  be  established,  and  the  stronger  solution  will  increase  in  quantity  until  the 
two  attain  the  same  density.  If  two  different  solutions  be  employed,  as,  for 
instance,  sugar  or  gum  within  the  tube,  and  potash  or  soda  without,  a  circula- 
tion will  in  like  manner  take  place,  the  preponderance  being  towards  the  denser 
fluid,  and  in  a  degree  proportionate  to  the  difference  in  density.  Instead  of  ani- 
mal membrane,  any  vegetable  matter  with  fine  pores,  such  as  a  thin  piece  of  wood, 
or  even  a  porous  mineral  substance,  may  be  substituted,  with  the  same  result. 


THICKENING    OF    THE    WALLS    OF    CELLS. 


lining.  Every  degree  of  this  secondary  deposition  occurs,  from  a 
slight  increase  in  the  thickness  of  the  membrane  to  the  filling 
up  of  the  greater  part  of  the  cavity  of  the  cell.  Any  hard  wood 
furnishes  illustrations  of  this.  Indeed,  the  difference  between  sap- 
toood  and  heart-wood  in  trees  is  principally  owing  to  the  increase 
of  tliis  deposit,  which  converts  the  former  into  the  latter ;  as  may 
be  seen  by  comparing,  under  the  microscope,  the  tissue  of  the  older 
with  that  of  the  newest  rings  of  wood, 
taken  from  the  same  tree.  Figures 
196  —  199  show  this  in  a  piece  of  oak 
wood.  Fig.  29  represents  a  highly 
magnified  cross-section  of  some  wood- 
cells  from  the  bark  of  a  Birch,  with 
their  calibre  almost  obliterated  in  this  way.  It  is  by  the  same 
process  that  the  stone  of  the  peach,  cherry,  &c.  acquires  its  extreme 
hardness.     Similar  indurated  cells  of  the  same  kind  are  met  with 

even  in  the  pulp  of  some 
fruits,  as  in  the  gritty  grains, 
which  every  one  has  noticed 
in  the  flesh  of  certain  pears, 
especially  of  the  poorer  sorts. 
A  section  of  a  few  cells  of  the 
kind  is  represented  in  Fig. 
27,  with  their  cavity  much 
reduced  and  rendered  very 
irregular  by  this  internal  in- 
crustation. Similar  cells  may 
be  found  in  some  parts  of  the  tissue  even  of  such  juicy  fruits  as  the 
cranberry  and  the  blueberry  (Fig.  28). 

42.  The  thickening  matter,  when  pure,  is  of  the  same  nature  as 
the  original  membrane  of  the  cell,  that  is,  it  consists  of  cellulose 
(27).  But  with  this  are  mingled  some  mineral  matters,  —  small 
quantities  of  which  must  needs  be  dissolved  in  the  water  which 
the  plant  imbibes  by  its  roots,  and  be  deposited  in  the  cells  of  the 

FIG.  27.  Magnified  section  of  the  gritty  cells  of  the  pear ;  the  cavity  almost  filled  with  an 
internal  deposit.  28.  Similar  cells  found  in  the  pulp  of  the  blueberry  (Vacciniuin  corym- 
bosum). 

FIG.  29.  Highly  magnified  cross-section  of  a  bit  of  the  old  liber  of  the  bark  of  the  Birch ; 
the  tubes  nearly  filled  with  a  deposit  of  solid  matter  in  concentric  layers.     (From  Link  ) 

FIG  SO.  Highly  magnified  wood-cells  (seen  in  transverse  and  longitudinal  section),  from 
the  root  of  the  Date  Palm  ;  showing  the  thickening  deposit  in  layers,  and  some  connecting 
canals  or  pits.     (From  Jussieu,  after  Mirbel.) 


36  THE    ELEMENTARY    STRUCTURE    OF    PLANTS. 

wood,  and  especially  in  those  of  the  leave;?,  where  much  of  the  water 
escapes  by  evaporation,  —  and  sometimes  certain  coloring  matters 
also,  such  as  give  the  different  tints  to  heart-wood,  &c.  Even 
when  purified  as  much  as  possible  from  all  admixture  of  foreign 
materials,  the  secondary  deposit  is  said  to  differ  a  little  from  cellu- 
lose, or  original  cell-membrane,  in  containing  a  somewhat  larger 
proportion  of  carbon  and  hydrogen  :  it  is  therefore  richer  in  combus- 
tible matter.  Forming  as  it  does  the  principal  part  of  the  weight 
of  wood  {lignum),  it  has  received  the  name  of  Lignine  (also  that  of 
Sclerogen)  ;  but  it  is  only  cellulose  a  little  modified.  This  differ- 
ence in  chemical  composition,  however,  shows  why  the  hard  woods, 
such  as  hickory  and  oak,  which  abound  in  this  lignified  deposit, 
should  be  more  valuable  for  fuel,  weight  for  weight,  than  the  soft 
woods,  which  have  little  of  it ;  at  least,  when  the  latter  are  not 
charged  with  resinous  matter.* 

43.  The  section  of  the  Avail  of  a  cell  thickened  by  internal 
deposit,  when  moderately  magnified,  commonly  appears  to  be  homo- 
geneous and  uniform.  But  under  a  high  magnifying  power  it  may 
often  be  distinguished  more  or  less  distinctly  into  successive  con- 
centric layers  (Fig.  27-31).  However  this  may  be,  it  rarely  hap- 
pens that  the  thickening  deposit  is  spread  evenly  over  the  whole 
inner  surface  of  a  cell.  It  is  commonly  interrupted  or  much  thinner 
at  some  places,  so  as  to  give  the  diminished  cavity  of  the  cell  very 
irregular  outlines  (as  in  Fig.  27,  28)  ;  or  else  it  is  wanting  at  cer- 
tain small  and  definite  spots,  which,  being  more  transparent,  when 
looked  down  upon  from  the  outside  appear  like  holes  or  pores  (Fig. 
32,  56,  57)  or  slits  (Fig.  58,  59),  according  to  their  shape.  In  this 
way  are  formed  the  various 

44.  Markings  of  the  Walls  of  Cells,  These,  whether  in  the  form  of 
bands,  spiral  lines,  dots,  or  apparent  pores,  all  arise  from  the  unequal 


*  From  the  manner  in  which  the  thickening  takes  place,  it  would  appear  that 
the  innermost  layers  must  always  he  the  most  recent.  But  M.  Trecul  has  con- 
vinced himself  that  the  primary  cell-membrane  sometimes  produces  a  secondary 
one  outside  of  itself,  as  well  as  on  the  inside,  so  that  the  original  cell-wall  is 
intermediate.  And  also,  that,  when  the  thickening  deposit  is  wholly  within  the 
primary  wall,  the  intermediate  layers  are  occasionally  secreted  in  some  way  by 
the  outer  or  inner  ones,  and  therefore  more  recent  than  the  inner.  Unlikely 
as  all  this  seems,  M.  Trc'cul's  investigations  are  entitled  to  great  attention. 
His  elaborate  memoir,  upon  Secondary  Formations  in  Cells,  is  published  in  the 
Annates  des  Sciences  Naturelles,  4th  scr.  Vol.  II.  1854. 


MARKINGS    OF    THE    WALLS    OP    CELLS. 


37 


nsfjp 


distribution  of  the  secondary  deposit.  They  are  portions  of  the 
Avails  which  are  either  thinner  or  thicker  than  the  rest.  These 
markings  display  the  greatest  variety  of  forms,  many  of  them  of 
surpassing  elegance.  The  principal  kinds  occur  with  perfect  uni- 
formity in  each  species  or  family,  and  in  definite  parts  of  the  plant ; 
so  that,  in  a  multitude  of  cases,  the  sort  of  plant  may  be  as  certainly 
identified  by  the  minute  sculpture  of  its  cells  alone,  as  by  more  con- 
spicuous external  characters.  They  are  preserved  even  when  the 
tissue  is  fossilized,  and  the 
external  form,  with  every  - 
outward  appearance  of  or- 
ganization, is  obliterated. 
Through  thin  slices  and 
other  contrivances,  the  hid- 
den structure  is  revealed 
under  the  microscope,  and 
thus  the  true  nature  of  the 
earth's  earliest  vegetation 
may  be  often  satisfactorily  made  out. 
In  this  way,  and  by  taking  advantage  of 
the  fact,  that  the  secondary  deposits  in 
the  cells  contain  a  good  deal  of  mineral 
matter,  which  is  left  behind  in  the  ashes, 
Professor  Bailey  was  able  first  to  dis- 
cover vegetable  structure  in  anthracite 
coal.*  The  simplest  and  commonest 
markings  are  those  which  appear  as 
pores  or  holes,  but  are  really 

45.  Dots  Of  Pits,  such  as  those  on  the 
cells  of  the  pith  of  Elder  (Fig.  38),  and 


*  See  Siiliman's  American  Journal  of  Science  and  Arts,  New  Series,  Vol.  I. 

FIG.  31.  Magnified  cross-section  of  a  small  portion  of  heart-wood  of  the  Plane-tree  or 
Buttonwood  (Platanus  occidentalis).  32.  A  corresponding  longitudinal  section,  parallel  with 
the  circumference,  a,  The  dotted  woody  tissue  ;  the  lower  ends  of  the  two  cells  to  which  the 
letters  are  appended  are  divided  lengthwise,  so  as  to  show  the  irregularly  thickened  calibre  ; 
the  others  are  mostly  entire,  showing  the  dots  :  in  the  cross-section  the  secondary  deposit  is 
seen  to  form  indistinct  layers,  and  some  of  the  dots  to  form  canals  of  lateral  communication. 
6,  Dotted  ducts  :  the  middle  one  in  the  longitudinal  section  is  obliquely  jointed,  c,  Medullary 
ray. 

FIG.  33.  Portion  of  four  cells  of  the  woody  tissue,  with  both  transverse  and  longitudinal 
section,  highly  magnified,  showing  the  canals  or  deep  pits  in  the  thickened  walls,  and  their 
apposition  in  adjoining  cells :  on  the  cross-section  the  layers  of  deposit  are  more  plainly  visible. 

4 


38 


THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 


upon  what  are  called  dotted  ducts  ;  as  in  Fig.  32,  b,  and  Fig.  56,  57. 
All  markings  of  tliis  kind  are  thin  spots,  which,  for  some  reason, 
have  not  partaken  in  the  general  thickening  of  the  wall.  Although 
they  are  not  primarily  pores  or  real  perforations,  yet  they  often  be- 
come so  with  age,  by  the  destruction  of  the  thin  primary  membrane, 
after  the  cell  has  lost  its  vitality.  Fig.  32  shows  these  dots  on  the 
wood-cells  and  the  ducts  of  the  Plane-tree.  And  Fig.  33,  represent- 
ing some  of  the  wood-cells  more  highly  magnified,  explains  their 
real  nature,  namely,  as  deep  pits  in  the  thick  wall.  It  will  be  seen 
that  the  pits  of  contiguous  cells  exactly  correspond ;  showing  that 
there  is  nothing  accidental  in  the  origin  or  the  arrangement  of  these 
markings.  They  are  manifestly  designed  for  maintaining  communi- 
cation between  contiguous  cells,  and  for  the  ready  conveyance  of  the 
sap  from  cell  to  cell,  notwithstanding  the  thickening  of  their  walls. 
Of  similar  nature,  although  of  greater  size,  are  the  so-called 


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46.  Discs  or  Circular  Markings  of  Coniferous  Wood  (Fig.  34-37). 

These  are  of  universal  occurence  in  the  wood  of  Pines,  Firs,  and  all 
that  family  of  Coniferous  trees ;  and  something  very  like  them,  if 
not  the  same,  occurs  in  the  Winter's-Bark  tree  (as  long  ago  shown 
by  Mr.  Brown),  the  Star- Anise,  and  even  in  the  Magnolia,  and  other 
aromatic  trees.  They  may  readily  be  seen  in  a  thin  Pine  shaving, 
taken  parallel  with  the  silver-grain :  for  in  the  Pine  family  they  are 
nearly  all  found  on  the  lateral  walls  of  the  cells,  few  or  none  being 
visible  on  the  sides  which  look  towards  the  bark  or  towards   the 

FIG.  34.  Piece  of  a  Pine  shaving,  magnified,  to  show  the  discs  or  thin  spots  which  appear 
on  the  cells  of  all  Coniferous  wood.    35.  A  separate  cell  of  the  above,  more  strongly  magnified. 

PIG.  36.  A  small  portion  of  five  cells  of  White-Pine  wood  magnified  ;  seen  both  in  trans- 
verse and  longitudinal  section,  a,  a,  discs,  in  transverse  section  :  6,  b,  discs  as  looked  down 
upon  in  longitudinal  view. 

FIG.  37.  A  highly  magnified  transverse  section  of  one  complete  wood-cell,  connected  with 
adjacent  cells,  and  of  a  disc  (a) :  after  Mohl. 


MARKINGS    OF    THE    WALLS    OF    CELLS. 


39 


pith ;  -while  the  smaller  dots,  of  the  ordinary  kind,  as  on  the  wood- 
cells  of  the  Plane-tree  (Fig.  32),  are  most  abundant  on  the  sides  that 
look  towards  the  centre  and  the  circumference  of  the  trunk.  The 
nature  of  these  disc-like  markings  is  plainly  revealed  in  the  accom- 
panying microscopical  dissections  of  White-Pine  wood  (Fig.  3G,  37). 
They  are  thin  places,  which  have  not  received  the  thickening  deposit 
that  has  lined  all  the  rest  of  the  calibre,  or  have  received  it  in  a 
lesser  degree.  Those  of  contiguous  wood-cells  always  exactly  cor- 
respond, just  as  do  the  smaller  dots  or  pits  of  ordinary  wood ;  and 
the  two  cell-membranes  separate  from  each  other,  each  being  some- 
what curved  inward,  thus  leaving  a  lenticular  space  between  them, 
like  that  between  two  watch-glasses  put  together  by  their  edges. 

47.  Bands,  Rings,  or  Spiral  Markings.  These  are  mostly  definite 
portions  of  the  wall  more  thickened  than  the  rest ;  as  is  shown  by 
the  spiral  vessel,  where  the  secondary  formation  is  restricted  to  a 
delicate  thread,  capable  of  being  unwound  (CO),  and  particularly 
by  the  remarkably  thick  plate  which  winds  around  in  the  cells  of 
certain  Cacti,  like  a  spiral  staircase  (Fig.  42,  43).  The  accompany- 
ing figures  illustrate  various  forms  of  banded,  reticulated,  or  spiral 
markings. 


48.  When  the  primitive  walls  of  such  banded  cells  remain  very 
thin  and  delicate,  they  are  apt  to  become  obliterated  at  maturity, 
leaving   the   firmer  fibrous    markings   as    separate   threads 


This 


FIG.  38.    A  cell  of  the  pith  of  Elder,  marked  with  oblong  dots,  which  are  thin  places. 

FIG.  39.     Cells  of  the  leaf  of  Sphagnum,  or  Peat-Moss,  marked  with  a  spiral  fibre. 

FIG.  40  -  43.     Spirally  banded  cells  from  species  of  Cactus,  after  Schleiden. 

FIG.  41.  Hairs  from  the  seed-coat  of  Dipteracanthus  strepens  ;  one  with  a  spiral  band,  the 
other  with  a  set  of  rings  developed  on  the  inner  surface  of  the  tube. 

FIG.  45.  Tissue  from  the  lining  of  the  anther  of  Cobsea  scandens ;  where,  the  delicate  walls 
of  the  cells  being  soon  obliterated,  nothing  but  the  fibrous  bands  with  which  they  were  marked 
remain. 


40  THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 

occurs  in  the  tissue  that  lines  the  walls  of  the  anther;  and  in  this 
way  the  spirally  marked  tubes  (called  Elaters)  which  occur  in  the 
spore-cases  of  the  Hepatic  Mosses  or  Liverworts  are  converted  into 
elastic  spiral  threads.     Of  a  similar  nature  are  the 

49.  Gelatinous  Coils,  or  soft  spiral  threads,  such  as  occur  in  the 
hairs  or  projecting  cells  which  invest  the  coats  of  many  seeds  or 
seed-like  fruits,  and  which  when  moistened  often  uncoil  and  are 
projected  from  the  bursting  cell  in  a  striking  manner.  When  water 
is  applied,  this  is  absorbed  by  endosmosis  (40),  the  gelatinous  threads 
swell,  burst  the  cell-membrane,  and  gush  out  in  the  form  of  uncoil- 
ing mucilaginous  fibres  or  bands.  Good  examples  of  the  kind  are 
furnished  by  the  seeds  of  Collomia  and  Gilia,  and  by  hairs  or  papilla? 
on  the  seed-like  fruits  of  numerous  species  of  Senecio  and  the  allied 
genera.  Those  of  Crocidium  project  a  thick,  mucilaginous,  twisted 
band,  in  place  of  a  thread.  They  may  subserve  a  useful  purpose  in 
fixing  light  seeds  to  the  ground  where  they  lodge,  by  means  of  the 
moisture  of  the  first  shower  they  receive. 


Sect.  III.     Of  the  Kinds  or  Transformations  of  Cellular 
Tissue  ;    viz.  Woody  Tissue,  Ducts,  etc. 

50.  The  statements  of  the  preceding  section  apply  in  general  to 
the  cells  of  which  all  plants  are  composed,  irrespective  of  the  mani- 
fold forms  they  may  assume,  and  of  some  peculiar  transformations 
they  may  undergo.  Some  of  these  should  now  be  specified ;  as 
they  give  rise  to  kinds  of  tissue  so  unlike  the  ordinary  cellular,  in 
outward  appearance  at  least,  that  they  have  always  been  distin- 
guished by  special  names.  We  allude  particularly  to  Woody  Tissue 
or  Woody  Fibre,  and  Vascular  Tissue  or  Vessels,  of  various  forms. 
These,  although  formerly  regarded  as  of  independent  origin,  are 
now  known  to  be  mere  modifications  of  one  common  type,  the  cell, 
and  are  produced  in  the  same  mode  as  ordinary  cells.  So  all  the 
statements  of  the  foregoing  section,  in  respect  to  the  formation,  mul- 
tiplication, and  growth  of  cells,  are  equally  applicable  to  these  also. 
Some  kinds  differ  from  ordinary  cells  in  shape  alone ;  others  result 
from  their  combination  or  confluence.  This  is  shown  in  two  ways : 
first,  by  noting  the  intermediate  gradations  which  may  be  found  be- 
tween every  particular  sort;  and  secondly,  by  watching  their  de- 
velopment and  tracing  them  directly  from  their  earliest  condition,  as 


rARENCIIYMA    AND    PROSEXCHYMA. 


41 


ordinary  cells,  to  the  peculiar  forms  they  soon  assume.  In  enumer- 
ating the  kinds  of  vegetable  tissue,  we  commence  with  cellular  tissue 
strictly  so  called,  or 

51.  Parenchyma.  This  is  the  distinctive  name  for  ordinary  mem- 
branous cellular  tissue  in  general,  such  as  that  which  forms  the  pith 
of  stems  and  their  outer  bark.  In  the  most  restricted  application,  it 
belongs  to  such  tissue  when  composed  of  angular  or  polyhedral  cells 
(as  in  Fig.  1-3,  9,  &c.)  ;  the  name  of  Merenchyma  having  been 
proposed  for  the  looser  tissues  (as  in  Fig.  7,  and  in  the  pulp  of 
leaves  and  fruits  generally),  formed  of  rounded  or  ellipsoidal  cells, 
that  is,  where  they  do  not  mutually  impress  each  other  into  plane 
faces.  But  this  distinction  vanishes  in  the  numberless  intermediate 
states ;  and  the  name  of  Parenchyma  is  applied  to  both.  That  in 
which  the  walls  touch  each  other,  more  or  less,  and  leave  interven- 
ing spaces  Avhere  the  ends  or  sides  are  rounded  off,  is  termed  by 
Schleiden  incomplete  •parenchyma  ;  and  that  in  which  the  cells  are  in 
perfect  contact  on  every  side,  complete  parenchy- 
ma. The  latter  is  regular,  when  the  cells  are 
dodecahedral  or  cubical ;  elongated  or  prismatic, 
when  extended  longitudinally ;  and  tabular,  when 
cubical  cells  are  much  flattened ;  one  kind  of 
which,  called  the  muriform,  because  the  laterally 
compressed  cells  appear  in  the  magnified  section 
like  courses  of  bricks  in  a  wall,  is  seen  in  the 
silver-grain  of  wood  (Fig.  192). 

52.  Froscncliyina  is  the  general  name  for  tissues 
formed  of  elongated  cells,  especially  those  with 
pointed  or  oblique  extremities.  Every  gradation 
may  be  traced  between  this  and  parenchyma.  As 
to  length,  such  cells  vary  from  fusiform,  or  spindle- 
shaped,  only  three  or  four  times  longer  than  broad, 
to  tubular,  and  to  tubes  so  long  and  narrow  that 
they  are  commonly  called  fibres.  The  most  char- 
acteristic form  of  prosenchyma  is 

53.  Woody  Tissue.  {Pleurenchyma  of  Meyer  and 
Lindley.  Woody  Fibre  of  the  older  authors.) 
Wood,  which  makes  up  so  large  a  part  of  trees 


FIG.  46.  Some  wood-cells  of  the  Plane-tree  or  Buttonwood,  highly  magnified  :  a,  thin 
spots  in  the  walls,  looking  like  holes  ;  on  the  right-hand  side,  where  the  walls  are  cut  through, 
these  (b)  are  seen  in  profile. 

4* 


42  THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 

and  shrubs,  .and  some  part  of  almost  all  ordinary  herbaceous  plants, 
is  wanting  in  Mosses  and  plants  of  still  lower  grades,  such  as 
Lichens,  Sea-weeds,  and  Fungi.  That  is,  in  the  latter  there  is  no 
formation  corresponding  to  the  wood  of  higher  plants,  although 
many  of  them  exhibit,  at  least  in  certain  parts,  cells  more  or  less 
elongated,  or  even  drawn  out  into  tubes  or  hollow  fibres  of  greater 
length  and  tenuity  than  are  those  of  ordinary  wood ;  such,  for 
instance,  as  the  interlaced  fibrous  tissue  of  Lichens  (Fig.  25). 
Nor,  on  the  other  hand,  does  the  proper  wood  of  trees  (except  in 
the  Pine  family)  consist  entirely  of  what  is  named  woody  tissue, 
but  has  some  other  sorts  variously  intermingled  with  it.  Indeed, 
there  are  some  trees  whose  wood  is  almost  entirely  composed 
of  true  parenchyma,  or  of  large  dotted  cells ;  while  in  stone-fruits, 
and  many  like  cases,  common  parenchymatous  cells  acquire  by  in- 
ternal deposit  (41)  a  ligneous  consistence,  and  even  greater  hardness 
than  ordinary  wood  (39).  Nevertheless,  the  principal  and  charac- 
teristic component  of  wood  in  general  is  thick-walled  prosenchyma. 
So  that  this  takes  the  name  of  woody  tissue  even  in  the  bark  and 
leaves,  as  well  as  in  the  trunk.  Fig.  32  represents  some  of  the 
various  elements  of  the  wood  of  the  Plane-tree.  And  Fig.  46  ex- 
hibits three  or  four  wood-cells  from  the  same  tree,  more  highly 
magnified ;  the  two  right-hand  ones  cut  through  lengthwise,  and 
one  of  these,  at  the  upper  end,  with  a  piece  of  another,  also  cut 
across,  to  show  the  thickness  of  the  walls. 

54.  This  and  the  following  figures  likewise  show  how  the  wood- 
cells  are  as  it  were  spliced  together,  overlapping  one  another  by 
their  tapering  ends.  Forming  wood  consists  of  oblong  or  plasmatic 
cells,  with  their  ends  nearly  square  or  merely  oblique :  as  these 
young  cells  lengthen,  the  ends  become  more  oblique,  and  push  by 
each  other,  or  become  wedged  together.  The  wood-cells  repre- 
sented in  Fig.  46  are  about  g-uW  of  an  inch  in  diameter.  Those  of 
our  Linden  or  Bass-wood  (a  few  of  which  are  shown  in  Fig.  50,  51) 
are  rather  larger,  but  not  more  than  y^gg-  of  an  inch  in  diameter.* 
Their  size  varies  in  different  plants  almost  as  much  as  ordinary  cells 
do,  but  they  are  usually  much  smaller  than  parenchyma,  especially 
in  herbaceous  plants.  Perhaps  the  largest  are  found  in  the  Pine 
family,  where  they  are  of  a  peculiar  sort,  and  are  often  as  much 

*  Lindley  states  that  the  woody  tuhes  of  the  Linden  are  as  much  as  ^^  of 
an  inch  in  diameter  ;  but  I  find  none  of  anything  like  this  size. 


WOODY    TISSUE. 


43 


a3  iretf  or  Zott  °f  an  incn  m  diameter.  The  density  or  closeness  of 
grain  in  wood,  however,  does  not  depend  so  much  on  the  fineness 
of  the  wood-cells  as  upon  the  thickness  of  their  Avails.  This  is 
much  greater  in  proportion  to  their  diameter  than  in  ordinary 
parenchyma,  and,  with  their  slenderness,  and  their  very  compact 
arrangement  into  threads  or  masses  which  run  lengthwise  through 
the  stem,  conspires  to  give  the  toughness  and  strength  which  charac- 
terize those  parts  in  which  this  tissue  abounds.  In  old  wood  of  the 
harder  kinds,  the  Avails  of  the  cells  become  so  thick  as  almost  to 
oblitei'ate  the  calibre  (Fig.  198).  The  thickening  is  generally  uni- 
form, giving  rise  to  no  markings  except  the  pits,  or  small  thin  spots, 
already  described  (45),  Avhich  appear  like  pores.  These  are  of  very 
general  occurrence,  and  are  readily  seen  in  the  wood  of  the  Plane- 
tree  (Fig.  32,  a,  46).  Markings  of  this  kind  are  most  conspicuous 
in  the  Disc-bearing  Woody  Tissue  (Glandular  Woody  Tissue  of 
Lindley)  of  the  Pine  Family,  the  nature  of  which  has  just  been 
explained  (46).  On  account  of  their  markings  and  their  unusual 
size,  and  because  in  the  Pine  family  they  make  up  the  wood  Avithout 
any  admixture  of  ducts,  these  pecu- 
liar Avood-cells  haAre  been  thought  to 
be  rather  a  form  of  vascular  tissue. 
But  in  the  Star-Anise  much  the 
same  kind  of  marking  is  found  on 
undoubtedly  genuine  woody  tissue 
(Fig.  47).  In  the  Yew,  on  the 
other  hand,  Avhere  the  discs  are 
feAV,  delicate  spiral  markings  appear 
(Fig.  48),  shoAving  a  transition  be- 
tAveen  the  proper  AAroody  and  the 
vascular  tissues ;  as  is  seen  by  com- 
paring the  figure  Avith  that  of  a 
spirally  marked  duct  of  Bass-Avood, 
Fig.  50,  a.  Here  the  thickening  deposit  is  in  two  successive  and 
dissimilar  layers ;  the  first,  Avith  circular  vacuities,  forming  the  discs, 
while  the  second  or  innermost  bears  the  spiral  markings. 


FIG.  47.  Magnified  woody  tissue  of  Illicium  Floridanum  (longitudinal  view),  marked  with 
large  dots,  like  the  discs  on  the  wood-cells  of  the  Pine  family. 

FIG.  48.  Magnified  woody  tissue  from  the  American  Yew  (longitudinal  view),  some  cells 
showing  delicate  spiral  lines  only  ;  some  showing  the  disc-like  markings  or  dots  of  ordinary 
Coniferaj ;  and  others  with  both  kinds  of  markings.  Across  the  base  is  seen  a  portion  of  a 
medullary  ray. 


44 


THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 


55.  Bast  Tissue,  or  Woody  Tissue  of  the  Liber.  The  bast  or  bass, 
fibrous  inner  bark,  or  liber,  as  it  is  variously  termed,  of  those  plants 
that  have  a  true  bark  separable  from 
the  wood  of  the  stem,  usually  consists  of 
or  contains  much  longer,  very  thick-sided, 
and  tougher,  but  more  soft  and  flexible 
cells,  than  those  of  the  wood  itself.  These 
properties  are  "  probably  given  them  that 
they  may  possess  the  strength,  combined 
with  flexibility,  which  their  position  near 
the  circumference  of  a  branch  renders 
necessary."  These  especially  adapt  them 
to  the  useful  purposes  they  so  largely 
subserve  for  clothing  and  cordage.  The 
textile  fibres  of  flax,  hemp,  &c.  are  all  de- 
rived from  this  woody  tissue  of  the  bark, 
separated  from  the  brittle  cells  of  the 
wood  itself,  and  freed  from  the  surround- 
ing thin-sided  parenchyma  by  macera- 
tion (which  soon  decomposes  the  latter) 
and  by  mechanical  means.*  The  length 
of  bast-cells  as  compared  with  wood-cells 
is  exemplified  in  the  accompanying  figures 
of  the  two,  from  our  Basswood  (Fig.  49 
-51).  The  difference  in  the  thickness 
of  the  walls  in  this  case  is  also  great ;  the  cells  of  the  soft  wood  hav- 
ing rather  thin  walls  even  when  old  (Fig.  52),  while  those  of  the 


*  Cotton  differs  from  linen  in  many  respects,  and  is  of  a  very  different  origin. 
It  consists  of  hairs,  or  long  tubular  cells,  growing  on  the  seeds  of  the  plant. 
These  have  very  thin  walls,  which  collapse  so  that  the  tube  flattens,  and  then 
twists  spirally,  which  gives  them  a  peculiar  adaptation  to  be  spun,  or  drawn  out 
together  by  torsion  into  a  thread,  contiguous  fibres  thus  moderately  clinging  to 
each  other  as  they  are  drawn  out.  But  they  have  not  such  thick  and  tough 
walls  as  liber-cells ;  so  a  cotton  fabric  is  not  so  heavy  nor  so  durable  as  linen. 


FIG.  49.  One  bast-cell,  and  part  of  another,  from  the  bark  of  American  Basswood.  50. 
Some  woody  tissue  from  the  wood  of  the  same,  with,  a,  upper  end  of  a  spirally-marked  duct. 
51.  A  separate  cell  from  the  wood.     All  magnified  to  the  same  degree. 

FIG.  52.  Transverse  section  of  some  wood-cells  of  the  Basswood,  highly  magnified.  53. 
Similar  section  of  some  bast-cells  from  the  bark  of  the  same  tree,  equally  magnified. 

FIG.  54,  55.  Ends  of  bast-cells  from  the  bark  of  the  Leather-wood  (Dirca  palustris),  mag- 
nified. 


VASCULAR    TISSUE.  45 

"bast  (Fig.  58)  are  so  extremely  thick-walled  as  almost  to  obliterate 
he  cavity.  The  disproportion  in  length  is  still  greater  in  our 
Leather-wood,  which  has  a  bark  of  extraordinary  toughness,  used 
for  thongs,  while  the  wood  is  very  brittle  and  tender.  Its  capillary 
bast-cells  measure  from  an  eighth  to  a  sixth  of  an  inch  in  length, 
with  an  average  diameter  of  STysTj  of  an  inch  (so  that,  if  the  whole 
length  of  a  cell,  magnified  as  in  Fig.  54,  55,  were  given,  the  figure 
would  be  from  a  foot  to  a  foot  and  a  half  in  length)  ;  while  those  of 
the  wood  itself  are  only  the  hundredth  of  an  inch  long.  Among  the 
bast-cells  are  found  the  longest  cells  which  occur  in  any  tissue.  Still 
the  individual  cells  are  by  no  means  absolutely  so  long  as  they  are 
supposed,  and  have  sometimes  been  stated,  to  be.  Few  are  of  such 
length  as  those  of  the  Leather-wood,  above  mentioned.  According 
to  Mold  (Bot.  Zeit.  1855,  p.  876)  there  are  few  plants  in  which 
they  exceed  the  twelfth  of  an  inch ;  but  he  has  found  them  an  inch 
long  in  Flax  and  in  our  common  Milkweed  (Asclepias  Cornuti),  and 
somewhat  longer  in  the  Nettle. 

56.  Woody  tissue  runs  lengthwise  through  the  stem,  root,  or  other 
organ ;  hence  it  is  sometimes  designated  as  Longitudinal  Tissue,  the 

Vertical  or  Longitudinal  System  of  the  stem,  &c.  It  shares  this 
name,  however,  with  some  other  forms  of  tissue  which  accompany 
it,  particularly  in  the  wood.  The  cells  which  compose  it  agree 
in  exhibiting  markings  of  some  kind  on  their  walls,  and  in  being 
larger  than  those  of  woody  tissue :  they  are  all  more  or  less  tubular, 
or  conspire  to  form  tubes  of  considerable  length,  and  hence  they  have 
all  been  combined,  in  a  general  way,  under  the  name  of 

57.  Vascular  Tissue  or  Vessels.    Not  to  be  misled  by  the  name,  it 

should  be  remembered  that  these  so-called  vessels  are  mere  modifica- 
tions of  cellular  tissue,  and  are  wholly  unlike  the  veins  and  arteries 
of  animals.  It  is  much  better  to  call  them  ducts,  a  name  appropriate 
to  their  nature  and  office,  and  leading  to  no  false  inferences.  Their 
true  nature  is  most  readily  shown  in  the  largest  and  most  conspicu- 
ous kind,  one  which  often  exhibits  unequivocal  indications  of  its 
cellular  origin,  viz. 

58.  Dotted  Duels,  called  also  Pitted  or  Vasiform  Tissue,  Bothren- 
chyma,  &c.  (Fig.  56,  57).  They  have  likewise  been  termed  Porous 
Cells  or  Porous  Vessels  ;  but  the  numerous  dots  that  characterize 
them  are  places  which  have  not  been  thickened  in  the  manner 
already  explained  (41,  44),  and  not  perforations,  except  in  old  cells, 
where  the  primary  membrane  may  be  obliterated.     Sometimes  they 


46 


THE    ELEMENTARY    STRUCTURE    OF    PLANTS. 


are  continuous  tubes  of  considerable  length  (Fig.  57)  ;  but  occasion- 
ally they  exhibit  cross-lines  at  certain  intervals,  plainly  showing  that 
they  are  made  up  of  a  row  of  cells  placed  end  to 
end,  and  becoming  a  tube  by  the  obliteration  of  the 
intervening  partitions  (Fig.  56).  In  Fig.  32  some 
dotted  ducts  (one  of  them  exhibiting  oblique  parti- 
tions or  ends)  are  shown  in  place  among  the  woody 
tissue.  It  is  in  the  wood  that  they  commonly 
abound.  Being  of  greater  calibre  than  any  other 
cells  or  vessels  found  there,  they  form  the  pores  so 
conspicuous  to  the  naked  eye  on  the  cross-section 
of  many  kinds  of  wood,  such  as  of  Oak,  Chestnut, 
56  57  and  Mahogany,  as  well  as  the  lines  or  channels 
seen  on  the  longitudinal  section.  Their  size,  compared  with  that  of 
the  wood-cells  in  the  wood  of  the  Plane-tree,  is  shown  both  in  longi- 
tudinal and  transverse  section,  in  Fig.  31,  32. 

59.  Scalariform  DuctS  (Fig.  58,  59),  differ  from  dotted  ducts  only 
in  the  form  of  the  markings,  the  thin  spots  being  transversely  elon- 
gated instead  of  circular,  and  appearing  like 
cross-bars,  which  have  been  likened  to  the 
rounds  of  a  ladder,  whence  the  name.  This 
is  the  more  striking  when  the  ducts  are  pris- 
matic (by  mutual  pressure)  and  the  cross-bars 
occupy  nearly  the  whole  length  of  each  side,  as 
in  Fig.  58.  Ducts  of  this  sort  abound  in  the 
stems  or  stalks  of  Ferns.  The  markings  are 
often  spiral  in  their  arrangement;  as  is  shown 
in  Fig.  59,  by  the  way  the  duct  tears  into  a 
band.  Ducts  of  this  and  of  the  foregoing  sort, 
where  the  markings  are  thin  places,  have  been 
named  by  Morren  and  Lindley  Bothrenchyma, 
meaning  pitted  tissue. 

60.  Reticulated,  Annular,  and  Spiral  Ducts  (Fig.  60-65),  on  the 

other  hand  (called  Trachea,  from  their  resemblance  to  the  windpipe, 
or  rather  to  the  trachete  or  air-tubes  of  insects),  have  been  distin- 
guished by  Morren  and  Lindley  under  the  general  name  of  Trachen- 
chyma.     In  these  the  markings,  at  least  in  most  cases,  are  thicker 

FIG.  56.  Fortion  of  a  dotted  duct  from  the  Vine,  evidently  made  up  of  a  series  of  short  cells. 

FIG.  57.  Fart  of  a  smaller  dotted  duct,  showing  no  appearance  of  such  composition. 

FIG.  58.  Scalariform  ducts  of  a  Fern,  rendered  prismatic  by  mutual  pressure. 

FIG.  59.  Similar  duct  of  a  Fern,  torn  into  a  spiral  band. 


VASCULAR    TISSUE. 


47 


places  than  the  rest  of  the  wall.  They  are  elongated  cells,  or  tubes 
formed  by  the  confluence  of  several  cells  into  one,  with  the  delicate 
walls  strengthened  by  the 
deposition  on  their  inner 
surface  of  additional  ma- 
terial, in  the  form  of  bands, 
sometimes  branching  and 
forming  network  (the  Re- 
ticulated duct),  as  in  the 
middle  of  Fig.  60,  or  of 
rings  (the  Annular  duct), 
as  in  the  middle  of  Fig. 
61,  or  of  a  continuous  spi- 
ral thread  (Fig.  62,  63),  or 
a  number  of  such  threads 
(Fig.  64),  thus  forming  the 
Spiral  duct  or  Spiral  vessel.  The  coiled  thread  has  been  generally 
thought  to  be  solid.  But  Trccul,  in  a  memoir  already  referred  to 
(42,  note),  insists  that  it  is  hollow,  and  it  really  appears  to  be  so  in 
the  thick  threads  or  bands  of  certain  cells  in  the  wood  of  several 
a  b  c  d  e  sorts  of  Cactus,  such  as  are  shown  in  Fig.  40  -  43, 
which  are  well  adapted  for  the  investigation  of 
this  point.  In  the  true  Spiral  Vessel  the  fibre  is 
so  strong  and  tough,  in  comparison  with  the  deli- 
cate membrane  on  which  it  is  deposited,  that  it 
may  be  torn  out  and  uncoiled  when  the  vessel  is 
pulled  asunder,  the  cell-wall  being  destroyed  in 
the  operation.  This  is  seen  by  breaking  almost 
any  young  shoot  or  leafstalk,  or  the  leaf  of  an 
Amaryllis,  and  gently  separating  the  broken  ends  ; 
when  the  uncoiled  threads  appear  to  the  naked 

FIG.  60.  A  portion  of  a  duct  from  the  leafstalk  of  Celery;  the  lower  part  annular;  the 
middle  reticulated,  and  the  thread  at  the  upper  part  broken  up  into  short  pieces. 

FIG.  61.  Duct  from  the  Wild  Balsam  or  Jewel-weed  ;  the  coils  of  the  thread  distant ;  a 
portion  forming  separate  rings. 

FIG.  G2.     A  simple  spiral  vessel,  torn  across,  with  the  thread  uncoiling. 

FIG.  63.     Two  such  vessels  joined  at  their  pointed  extremities. 

FIG.  61.     A  compound  spiral  vessel,  partly  uncoiled,  from  the  Banana. 

FIG.  65.  A  bundle  of  spiral  ducts  from  the  stem  of  Prince's  Feather  (Polygonum  orientale), 
magnified  :  o,  one  composed  of  short  cells  and  with  the  fibre  closely  coiled  :  the  next,  b,  is 
composed  of  much  longer  joints,  and  ha^  a  very  loose  coil :  c  is  short-jointed,  and  the  filre  of 
the  loose  coil  is  occasionally  forked  :  d  and  e  show  no  appearance  of  joints  or  partitions,  and 
the  turns  of  the  spiral  fibre  are  still  more  remote. 


48  THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 

eye  like  a  fine  cobewb.  In  stems  furnished  with  pith,  the  spiral 
vessels  usually  occupy  a  circle  immediately  around  it.  They  occur 
also  in  the  veins  of  the  leaves,  and  in  all  parts  which  are  modifi- 
cations of  leaves.  More  commonly  the  coil  is  formed  of  a  single 
fibre,  as  in  Fig.  62,  63  :  it  rarely  consists  of  two  fibres ;  but  not 
uncommonly  of  a  considerable  number,  forming  a  band,  as  in  Fig. 
G4.  Spiral  vessels  of  the  latter  kind  are  to  be  found  in  an  Aspara- 
gus shoot,  and  are  finely  seen  in  the  stems  of  the  Banana.  From 
the  Musa  textilis  of  Manilla,  of  the  same  genus  as  the  Banana, 
these  cobwebby  fibres  are  said  to  be  extracted  in  large  quantities, 
and  used  in  the  production  of  the  most  delicate  of  textile  fabrics. 

Gl.  True  spiral  vessels,  capable  of  uncoiling,  occur  in  all  plants 
of  the  higher  grades,  but  only  in  particular  parts.  Reticulated  and 
annular  ducts  abound  in  most  herbaceous  stems ;  and  every  transi- 
tion may  be  detected  between  the  various  kinds.  Fig.  65  shows  a 
number  of  variations,  such  as  may  be  seen  at  one  view  in  the  stem 
of  a  Polygonum.  Some  have  the  fibre  closely  coiled ;  in  others  the 
turns  are  distant.  Some  are  simple  tubes,  and  apparently  formed  of 
a  single  elongated  cell :  others  show  cross  partitions,  or  vestiges  of 
them,  and  so  are  made  up  of  a  row  of  cells ;  and  if  these  be  com- 
pared with  Fig.  39  —  43,  &c,  it  will  plainly  appear  that  ducts  of  all 
sorts  are  only  a  modification  of  ordinary  cells.  Even  the  longest 
are  of  no  great  length ;  very  rarely  are  they  above  half  an  inch 
long ;  and  they  terminate  by  closed  ends,  like  all  other  cells ;  the 
termination  being  either  abrupt  or  more  commonly  conical  or  ob- 
tusely pointed.  In  young  parts  the  ducts,  like  other  cells,  contain 
liquid,  the  ordinary  juices  of  the  plant:  in  older  stems  they  arc 
filled  with  air,  except  when  the  whole  tissue  is  gorged  with  sap, 
which  then  finds  its  way  into  these  also. 

62.  Interlaced  Fibrilliform  Tissue.    This  is  quite  as  distinct  from 

ordinary  cellular  tissue,  and  as  worthy  of  a  special  name,  as  any  of 
the  kinds  already  described.  It  is  the  more  worthy  of  notice, 
from  its  near  resemblance  to  some  forms  of  animal  tissue.  It 
consists  of  very  long,  much  attenuated,  simple  or  branching,  fibre- 
like cells,  or  strings  of  cells,  inextricably  entangled  or  interwoven 
without  order,  so  as  to  make  up  a  loose,  fibrous  tissue.  It  is  prin- 
cipally met  with  in  Fungi,  Moulds,  &c,  where  the  cells  are  ex- 
tremely soft  and  destructible ;  and  in  Lichens  (Fig.  25),  where  it  is 
dry  and  much  firmer.  A  remaining  and  a  very  ambiguous  element 
of  vegetable  fabric  is 


VESSELS    OF    THE    LATEX. 


49 


63.  LatidferoUS  Tissue.  (Vessels  of  the  Latex  or  Milky  Juice. 
Ginenchyma  of  Morren  and  Lindley.)  This  consists  of  long  and 
irregular  branching  tubes  or  passages,  lying  in  no  definite  position 
with  respect  to  other  tissue,  and  when  young  of  such  extreme  tenu- 
ity (their  average  diameter  being  less  than  the  fourteen-hundredth 
of  an  inch)  and  of  such  trans- 
parency that  they  are  hardly 
visible,  even  under  powerful  mi- 
croscopes, except  by  particular 
manipulation.  But  their  older 
trunks  are  larger  and  more  evi- 
dent, when  gorged  with  the  milky 
or  other  special  juices  which  it  is 
their  office  to  contain,  and  when 
their  sides  are  thickened  by 
the   deposition  of  such  matters. 

Another  peculiarity  is,  that  they  anastomose  or  inosculate,  forming 
a  sort  of  network  by  the  union  of  their  branches,  so  that  they  freely 
communicate  with  each  other.  In  this  respect,  as  well  probably  as 
in  the  mode  of  their  formation,  they  resemble  the  veins  of  animals. 
But  their  branches  do  not  proceed  from  larger  trunks,  and  in  turn 
divide  into  smaller  branchlets.  They  merely  fork  and  inosculate 
here  and  there,  the  branches  being  commonly  as  large  as  the  trunk 
before  division.  The  articulations  which  they  often  present  (as  in 
the  upper  part  of  Fig.  67)  would  seem  to  prove  that  they  are  formed 
by  the  confluence  of  cylindrical  cells.  It  is  altogether  most  probable, 
however,  that  they  are  not  composed  of  cells  at  all ;  but  are,  at  first, 
mere  passages  in  the  intercellular  spaces,  which  in  time  are  bounded 
by  walls  formed  by  deposition  from  the  contained  fluid.  Schultz, 
who  discovered  these  peculiar  vessels  and  gave  to  them  their  present 
name,  describes  a  regular  circulation  of  the  juice  they  contain ; 
which  would  make  them  still  more  analogous  to  the  vessels  or  veins 
of  animals.  But  this  has  been  shown  to  have  no  real  existence. 
There  is  merely  a  mechanical  flow  from  any  part  under  pressure,  or 
towards  a  place  from  which  the  latex  is  escaping,  as  from  a  wound. 
Laticiferous  vessels  occur  in  the  bark,  especially  in  the  liber,  in  the 
leafstalks,  and  in  the  leaves,  especially  of  those  plants  which  have 
a  milky  juice. 

FIG.  66.     Vessels  of  the  latex,  ramifying  among  cellular  tissue,  in  the  Dandelion  ;  and  67, 
older  and  larger  vessels  from  the  same  plant ;  all  highly  magnified. 

5 


50  THE    ELEMENTARY    STRUCTURE    OF    PLANTS. 

G4.  All  the  different  kinds  of  tissue  that  enter  into  the  composi- 
tion of  the  plant  have  now  been  described,  and  all  (excepting  the 
doubtful  latex-vessels)  referred  to  the  cell  as  their  original.  Every 
plant,  or  each  organ,  consists  at  first  of  one  or  more  cells  of  proper 
cellular  tissue.  In  many  of  the  simpler  vegetables,  the  cells  multi- 
ply in  this  primitive  form  solely ;  and  the  fully  developed  plant  con- 
sists of  parenchyma  alone.  But  in  all  plants  of  the  higher  grades, 
some  of  them  early  assume  the  forms  of  wood-cells  and  of  ducts. 
These  modified  cells  always  lie  vertically  in,  or  conspire  to  form, 
bundles  or  cords  that  run  lengthwise  tln-ough,  the  stem  or  other 
organ  they  occur  in.  They  are  associated  with  each  other,  and 
together  make  up  the  woody  parts,  as  in  the  wood  proper,  in  the 
fiber  or  inner  bark,  and  in  the  fibrous  framework  of  the  leaves. 
Although  the  various  kinds  exhibit  transitions  through  every  man- 
ner of  intermediate  forms,  the  whole,  taken  together,  compose  tissues 
which  are  almost  always  manifestly  different  from  the  parenchyma 
in  which  they  are  imbedded.  It  is  convenient,  therefore,  to  give 
them  a  general  name,  and  to  denominate  them,  from  their  position, 
the  Vertical  or  Longitudinal  System,  or,  from  their  nature,  the 
Fibro-vascidar  or  Woody  System ;  in  contradistinction  to  the  Hori- 
zontal or  common  Cellular  System  of  the  plant,  consisting  of  paren- 
chyma alone. 

65.  Intercellular  System.  The  only  exception  to  the  statement 
that  all  the  vegetable  tissues  are  formed  of  cells,  is  that  of  the 
so-called  vessels  of  the  latex,  which,  according  to  the  view  now  best 
supported,  are  a  secondary  formation,  resulting  from  the  transuda- 
tion of  peculiar  assimilated  matters  into  the  interspaces  between  the 
cells ;  and  are  therefore  rather  to  be  classed  with  other  receptacles, 
canals,  or  intervals  that  are  found  among  or  between  the  cells. 
Some  of  these  are  accidental,  or  at  least  are  irregular  and  indefi- 
nite: such  are  the  Intercellular  Spaces  or  Passages,  left 
when  the  cells  are  not  in  contact  throughout.  Of  the  same  char- 
acter are  the  larger  and  irregular  spaces  in  the  lower  stratum  of 
the  tissue  of  most  leaves  (Fig.  7  and  Fig.  221),  and  which  form 
irregular  winding  passages  through  which  the  air,  admitted  through 
the  stomates  (70),  freely  circulates. 

66.  Air-PassagCS,  however,  are  not  always  so  irregular.  The  stalks, 
and  often  the  foliage  also,  of  aquatic  and  marsh  plants  generally 
abound  with  regular  air-channels,  of  much  greater  diameter  than 
the  cells  of  the  tissue.     These  air-passages  are  symmetrically  ar- 


INTERCELLULAR   AND    EPIDERMAL    SYSTEMS.  51 

ranged,  and  are  as  elaborately  constructed  as  any  proper  organ  can 
be.  They  are  built  up  of  cells  in  a  manner  wliich  may  be  compared 
to  a  stack  of  flues  or  chimneys  built  of  brick :  they  are  constructed 
upon  a  uniform  plan  in  each  species,  and  are  evidently  essential 
parts ;  plants  which  grow  in  water  requiring  a  full  supply  of  air 
in  their  interior.  Fig.  G8  shows  some  of  these  air-passages  in  the 
flower-stalk  of  Calla  iEthiopica. 


67.  Receptacles  Of  Special  Secretions.  These  arise  from  the  exuda- 
tion of  the  proper  juices  of  the  cells  into  intercellular  passages, 
which  are  distended  by  the  accumulation ;  or  from  the  obliteration 
of  contiguous  cells,  so  as  to  form  cavities  of  considerable  size.  Such 
are  the  turpentine-canals  of  the  Pines,  &c. ;  the  oil-cells  of  the 
fruit  of  the  Urubelliferre,  and  those  in  the  rind  of  the  orange  and 
lemon ;  the  latex-canals  in  Sumach,  &c.  Internal  Glands,  such  as 
those  which  form  the  translucent  dots  in  the  leaves  of  the  Orange 
and  Myrtle,  are  little  clusters  of  cells,  filled  with  essential  oil. 

68.  Epidermal  System.  In  most  plants,  except  of  the  lowest  grades, 
and  those  which  grow  under  water,  the  superficial  layer  of  cells  is 
different  from  the  rest,  and  forms 

69.  The  Epidermis,  or  skin  of  the  plant.  This  consists  of  one  or 
more  layers  of  empty  thick-walled  cells,  cohering  so  as  to  form  a 
firm  and  close  membrane,  which  may  be  detached  from  the  subjacent 
tissue.  It  covers  all  parts  of  the  plant  which  are  directly  exposed  to 
the  air,  except  the  stigma.  Its  structure  and  office  will  be  described 
in  the  chapter  on  the  Leaves.  The  epidermis  forms  a  complete 
and  continuous  covering,  except  that  in  certain  parts,  especially  on 
the  lower  surface  of  the  leaves,  it  is  perforated  by  a  multitude  of 
small  openings,  called 

FIG.  68.  A  magnified  slice  across  part  of  the  flower-stalk  of  Calla  ^ithiopica  of  our  green- 
houses, showing  the  large  air-passages,  built  up  of  cells  j  nearly  in  the  centre,  a  bundle  of 
woody  tissue  is  seen  in  cross-section. 


52  THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 

70.  Stomates  (Stomata)  or  Breathing-Pores.  These  have  a  peculiar 
structure,  the  opening  being  guarded  usually  by  a  pair  of  thin-walled 
cells,  so  arranged  as  to  close  or  open  according  to  circumstances. 
They  will  also  be  illustrated  in  the  chapter  on  the  Leaves,  to  which 
they  more  particularly  belong. 

71.  Ilairs  are  external  prolongations  of  cells  of  the  epidermis,  con- 
sisting either  of  single  elongated  cells,  or  of  several  cells  placed  end 
to  end,  or  of  various  combinations  of  such  cells.  They  are  simple 
or  branched,  single  or  clustered  (stellate,  &c),  and  exhibit  the 
greatest  variety  of  forms.  In  what  are  called  Glandular  Hairs,  or 
Stalked  Glands,  the  upper  cell  or  cluster  of  cells  has  a  peculiar 
structure,  and  elaborates  peculiar  (usually  odorous)  products,  such 
as  the  fragrant  volatile  oil  of  the  Sweetbrier. 

72.  Glands.  This  name  is  applied  to  any  secreting  apparatus,  and 
especially  to  superficial  appendages  of  the  epidermis  which  elaborate 
odorous  or  other  products. 

73.  StillgS,  or  Stinging  Hairs,  such  as  those  of  the  Nettle,  gener- 
ally consist  of  a  rigid  and  pointed  cell,  borne  on  an  expanded  base, 
or  gland,  which  secretes  an  irritating  fluid. 

74.  Bristles  (Setce)  are  rigid,  thick-walled  hairs,  usually  of  a  single 
cell.  But  the  name  is  likewise  given  to  any  similar  bodies,  of  what- 
ever nature. 

75.  Prickles  are  larger  and  indurated,  sharp-pointed  processes  of  the 
epidermis  or  the  bark  (but  not  of  the  wood)  ;  such  as  those  of  the 
Rose  and  Blackberry. 

76.  Scurf,  or  Lepidote,  Scale-like  Hairs,  are  flattened,  star-like 
clusters  of  cells,  united  more  or  less  into  a  sort  of  scale,  which  is 
fixed  by  its  centre  to  the  epidermis.  They  are  well  shown  in  the 
Oleaster,  Shepherdia,  and  most  silvery  leaves  like  theirs.  Our 
species  of  Vesicaria  exhibit  beautiful  gradations  between  these  and 
stax*-shaped  {stellate)  hairs. 


Sect.  IV.     Of  the  Contents  of  Cells. 

77.  These  comprise  all  the  products  of  plants,  and  also  the 
materials  plants  take  in  from  winch  these  products  are  elaborated. 
To  treat  of  them  fully  would  anticipate  the  topics  which  belong  to 
the  chaffer  on  Nutrition.  Some  of  the  contents  of  cells,  however, 
have  already  been  mentioned,  in  the  account  of  their  production  and 


SAP,   SUGAR,   ETC.  53 

growth  (27-40)  :  others  require  a  brief  notice  here,  especially  two 
solid  products  which  are  of  nearly  universal  occurrence  and  of 
great  importance  in  the  vegetable  economy,  namely,  Chlorophyll  and 
Starch. 

78.  The  same  cells  contain  liquids,  solids,  and  air,  at  different 
a^es.  Growing  and  vitally  active  cells  are  filled  with  liquid  (at 
least  while  vital  operations  are  carried  on),  namely,  with  water 
charged  more  or  less  with  nutritive  assimilated  matters,  the  pre- 
pared materials  of  growth  (11,  27).  Any  air  they  may  contain  at 
this  period  is,  for  the  most  part,  held  in  solution.  Completed  cells 
may  still  be  filled  with  liquid,  or  with  air,  or  with  solid  matter  only. 
The  liquid  contents  of  the  vegetable  tissues,  of  whatever  nature  or 
complexity,  are  generally  spoken  of  under  the  common  and  some- 
what vague  name  of 

79.  Sap.  In  employing  this  name  we  must  distinguish,  first, 
Crude  Sap  ;  the  liquid  which  is  imbibed  by  the  roots  and  carried 
upwards  through  the  stem.  This  is  water,  impregnated  with  certain 
gaseous  matters  derived  from  the  air,  and  with  a  minute  portion  of 
earthy  matter  dissolved  from  the  soil.  It  is  therefore  inorganic  (12). 
But,  as  it  enters  the  roots  and  traverses  the  cells  in  its  ascent,  it 
mingles  with  the  liquid  or  soluble  assimilated  matters  which  these 
contain,  so  that  unmixed  crude  sap  is  never  met  with  in  the  plant. 
On  reaching  the  leaves,  a  part  of  the  inorganic  materials  of  the 
ascending  sap  are  transformed,  under  the  influence  of  fight,  into 
organizable  or  assimilated  matter ;  and  the  liquid,  thus  charged  with 
the  prepared  materials  of  growth,  is  now  Elaborated  Sap.  The 
nutritive  matter  of  the  elaborated  sap  is  of  two  general  kinds : 
1.  The  ternary,  which  consists  of  only  the  three  elements,  carbon, 
hydrogen,  and  oxygen ;  and  2.  The  quaternary,  which  consists  of 
four  elements,  viz.  of  nitrogen  in  addition  to  those  just  mentioned. 
Sugar  and  dextrine,  or  dissolved  starch,  are  representatives  of  the 
first  class ;  and  these  have  nearly  the  same  chemical  composition  as 
cellulose  or  cell-membrane.  Protoplasm  or  proteine  represents  the 
second  class  (27). 

80.  Sugar  (of  which  there  are  two  distinct  kinds,  Cane  and  Grape 
Sugar)  is  the  most  soluble  form  of  ternary  organizable  matter. 
Though  sometimes  crystallized  as  an  excretion  in  the  nectaries  of 
flowers,  yet  in  the  plant  it  exists  only  in  solution.  It  abounds  in 
growing  parts,  in  many  stems  just  before  flowering,  as  those  of  the 
Sugar-cane,  Maize,  Maple,  &c,  in  pulpy  fruits,  and  in  seeds  when 

5* 


54 


THE    ELEMENTARY    STRUCTURE    OF   PLANTS. 


they  germinate ;  and  is  the  appropriate  prepared  material  for  the 
plant's  nourishment  and  growth.  Dextrine  is  a  substance  inter- 
mediate in  nature  between  sugar  and  starch. 

81.  Starch  {Farina,  Feculd)  is  one  of  the  most  important  and 
universal  of  the  contents  of  cells,  in  which  it  is  often  accumulated 
in  great  quantity,  so  as  to  fill  them  completely  (Fig.  70)  ;  as  in 

farinaceous  roots, 
seeds,  &c.  It  oc- 
curs in  the  pa- 
renchyma of  al- 
most every  part 
of  the  plant,  ex- 
cepting the  epi- 
dermis :  but  while  chlorophyll  is  nearly  restricted  to  the  superficial 
parts,  directly  exposed  to  the  light,  starch  is  most  abundant  in  inter- 
nal or  subterranean  parts,  concealed  from  the  light,  as  in  roots  and 
tubers,  the  pith  of  stems,  and  seeds.  Starch  consists  of  transparent 
oval  or  rounded  grains,  sometimes  becoming  angular  by  mutual 
pressure,  as  in  rice.  The  size  of  the  grains  varies  extremely  in 
different  plants,  and  even  in  the  same  cell ;  as  in  the  potato,  where 
the  larger  grains  measure  from  -^\^  to  ^^  of  an  inch  in  their  larger 
diameter,  but  the  smallest  only  j^gxy  of  an  inch.  In  wheat-flour  the 
larger  grains  are  -g-^y  to  -g^  of  an  inch  in  diameter.  And  the 
largest  starch-grains  known  are  g-^  of  an  inch  long.  Indeed,  from 
their  formation,  we  might  expect  that  their  bulk  would  vary  con- 
siderably. The  mode  of  their  formation  is  indicated  by  the  peculiar 
markings,  by  which  most  starch-grains  may  be  recognized ;  namely, 
by  the  dot  or  darker  point  which  is  seen  commonly  near  one  end  of 
the  grain,  and  the  fine  concentric  lines  drawn  around  it.  These  are 
best  seen  in  starch  from  the  potato,  one  of  the  most  characteristic 
forms  and  easiest  to  be  examined,  under  a  magnifying  power  of 
from  250  to  500  diameters  (Fig.  69).  The  chemical  composition 
of  starch  is  exactly  the  same  as  that  of  cellulose  (27)  ;  and  the 
grains  are  solid  throughout,  but  their  interior  usually  softer  or  more 
gelatinous.  The  lines  evidently  show  that  starch-grains  consist  of 
concentric  layers,  of  different  density,  successively  deposited  on  an 


FIG.  69.  Two  cells  of  a  potato,  with  some  contained  starch-grains,  highly  magnified  ;  one 
of  the  cells  contains  a  few  cubical  crystals  also. 

FIG.  70.  A  minute  portion  of  Indian  meal,  strongly  magnified  ;  the  cells  absolutely  filled 
with  grains  of  starch. 


STAKCH,    AMYLOID.  55 

original  nucleus.  The  layers  are  commonly  much  thicker  on  one 
side  than  the  other,  so  that  the  dot  or  nucleus,  which  all  the  lines 
surround,  becomes  very  eccentric.  Starch-grains  lie  loose  in  the 
cell  where  they  are  formed,  and  are  usually  separate  and  simple. 
But  occasionally  two  or  more  small  grains  are  combined  by  new 
layers  into  one,  and  in  some  plants  they  are  regularly  united  into  a 
cluster  or  compound  grain,  as  in  West-India  Arrowroot,  the  corms 
of  Colcliicum  and  Arum,  and  the  rootstocks  of  the  Water-Lily 
(Xvmphoea)  and  Water-Shield  (Brasenia).  In  the  latter  the  grains 
are  oblong  or  club-shaped,  and  remarkably  large.  Starch-grains  are 
nearly  uniform  in  the  same  plant  or  organ,  and  of  very  different 
appearance  in  different  plants :  so  that  the  smallest  quantity  of 
Starch  from  the  potato,  wheat,  rice,  maize,  arrow-root,  &c,  may  at 
once  be  distinguished  under  the  microscope.  In  this  way  adultera- 
tions of  arrow-root,  &c.  may  be  detected.  The  outer  layers  of 
large  and  well-developed  starch-grams  (such  as  those  of  the  potato) 
are  denser  than  the  inner :  consequently,  each  grain  is  marked  by  a 
dark  cross  when  viewed  by  polarized  light.  Starch  is  unaffected 
by  cold  water ;  but  hot  water  is  absorbed  by  it ;  the  inner  part  of 
the  grain  softens  first  and  swells,  inflating  the  denser  superficial 
portion  into  a  large  sac,  which  may  at  length  burst  or  be  dissolved. 
It  thus  forms  a  jelly  with  boiling  water,  but  is  not  really  soluble  in 
it.  When  truly  dissolved,  it  is  no  longer  starch,  but,  by  a  slight 
change  in  its  character,  it  is  changed  into  dextrine  (80).  The 
chemical  test  of  starch  is  iodine,  wMch  turns  it  blue. 

82.  Starch  is  the  form  in  which  nourishing  matter  is  stored  up  in 
the  plant  for  future  use ;  in  which  respect  it  may  be  likened  to  the 
fat  of  animals.  It  is  the  ready-prepared  material  of  vegetable  fabric. 
—  the  same  as  cellulose  in  a  particular  and  more  soluble  form, — 
accumulated  in  the  cells  of  certain  parts  as  a  provision  for  future 
growth.  When  about  to  be  used,  the  grains  are  dissolved  in  the 
plant  at  the  natural  temperature ;  that  is,  the  starch  is  converted  into 
dextrine,  which  differs  chiefly  in  being  soluble  in  cold  water,  and  this 
changes  into  sugar,  which  is  still  more  soluble ;  and  thus  a  sirup  is 
formed,  which  the  sap  dilutes  and  conveys  to  the  adjacent  parts,  or 
to  wherever  growth  is  going  on. 

83.  Amyloid  (of  which  Bassorin,  Salep,  and  Pectine  are  apparently 
modifications),  which  in  solution  is  Vegetable  Jelly,  is  intermediate  in 
character  between  starch,  dextrine,  and  cellulose,  and  has  nearly  the 
properties  of  starch,  when  this  has  been  altered  by  hot  water.     It 


56  THE    ELEMENTARY    STRUCTURE    OF    PLANTS. 

abounds  in  the  almond,  bean,  and  some  other  esculent  seeds,  in  the 
tubers  of  Orchises  (as  Salep,  &c.),  and  forms  the  principal  substance 
of  many  sea- weeds,  such  as  the  Carragheen  Moss  (Chondrus  crispus), 
from  which  jelly  is  obtained  for  culinary  purposes.  When  dry,  it  is 
horny  or  cartilaginous,  and  lines  the  cells ;  when  moist,  it  swells 
up,  becomes  gelatinous,  and  is  capable  of  being  perfectly  diffused 
through  cold  water.  We  have  it  as  an  excretion  in  Gum  Traga- 
canth.  True  gums,  such  as  Gum  Arabic,  are  states  of  nearly  the 
same  substance,  and  are  likewise  formed  only  as  excretions. 

84.  Fixed  Oils  belong  to  the  class  of  ternary  products,  but  they 
contain  little  oxygen,  and  some  of  them  none  at  all.  The  fatty  oils 
take  the  place  of  starch  in  the  seeds  of  many  plants  (as  in  flax-seed, 
walnuts,  &c),  and  of  sugar  in  some  fruits,  such  as  the  olive.  They 
also  occur  in  the  herbage  of  most  plants. 

85.  Wax  is  a  product  of  nearly  the  same  nature  as  the  fixed  oils, 
only  it  is  solid  at  the  ordinary  temperature.  It  occurs  as  an  excre- 
tion, particularly  on  the  surface  of  leaves  and  fruits,  forming  the 
bloom  or  glaucous  surface  which  repels  water,  and  so  prevents  such 
surfaces  from  being  wetted.  It  forms  a  thick  coating  on  some  fruits, 
as  the  bayberry.  Wax  also  exists  in  all  herbage,  being  one  of  the 
components  of  the  green  matter  of  plants  (92). 

86.  Vegetable  Acids.  Tartaric,  Citric,  and  Malic  Acids  are  the 
principal  kinds ;  they  are  found  in  the  herbage  of  those  plants  which 
have  a  sour  juice,  such  as  Sorrel  and  the  Grape-Vine.  They  are 
ternary  products,  with  a  larger  proportion  of  oxygen  than  starch, 
sugar,  and  the  like.  They  do  not  appear  to  play  any  leading  part 
in  vegetation.  They  seldom  exist  in  a  free  state,  but  are  combined 
with  the  alkaloids,  and  with  the  inorganic  or  earthy  alkalies  (Potash, 
Soda,  Lime,  and  Magnesia),  which  are  introduced  into  plants  from 
the  soil  with  the  water  imbibed  by  the  roots.  The  more  soluble 
salts  thus  produced  are  found  dissolved  in  the  sap ;  the  more  insolu- 
ble are  frequently  deposited  in  the  cells,  either  as  an  incrustation  of 
their  Avails,  or  in  the  form  of  minute  crystals.  When  these  crystals 
contain  a  vegetable  acid,  it  is  almost  always  Oxalic  Acid.  This  is 
an  almost  universal  vegetable  product,  and  is  a  binary  body  (that  is, 
consists  of  two  elements  only,  carbon  and  oxygen),  differing  from 
carbonic  acid  in  ultimate  composition  only  in  having  a  little  more 
oxygen.  Hydrocyanic  or  Prussic  Acid  is  one  of  the  special  pro- 
ducts peculiar  to  certain  plants,  and  of  very  different  composition, 
containing  a  large  portion  of  nitrogen. 


OILS,    ACIDS,    ALKALOIDS,    ETC.  57 

87.  Tanilin  or  Tannic  Acid,  which  most  abounds  in  older  bark,  is 
probably  a  product  of  the  oxidation  or  commencing  decomposition 
of  the  tissues.  So,  also,  Humus,  Humic  Acid,  Uhnine,  Ulmic  Acid, 
and  the  numerous  related  substances  distinguished  by  the  chemists, 
are  products  of  further  decomposition  of  vegetable  tissue,  rather 
than  true  products  of  vegetation. 

88.  Essential  Oils,  Turpentine,  Caoutchouc,  &c.    These  are  some  of 

the  Proper  Juices  of  plants,  peculiar  to  certain  plants,  and  occurring 
under  a  great  variety  of  forms  in  different  species.  It  is  not  known 
that  they  are  of  any  account  in  vegetable  growth  or  nutrition.  They 
undergo  changes  on  exposure  to  the  air,  and  become  resins,  gums, 
&c.  They  are  apt  to  be  accumulated  in  intercellular  cavities,  or  to 
be  excreted  from  the  surface  of  the  plant.  Not  knowing  of  what 
use  they  are  to  the  vegetable,  Ave  are  inclined  to  regard  them  as  of 
the  nature  of  excretions.  Caoutchouc  exists  in  the  form  of  minute 
globules,  diffused  as  an  emulsion  in  the  milky  juice  of  plants,  of 
various  families.  The  original  India-Rubber  of  the  East  Indies  is 
the  milky  juice  of  a  species  of  Fig.  That  of  South  America,  now 
so  largely  used  for  a  great  variety  of  purposes,  comes  from  certain 
trees  of  the  Euphorbia  family.  It  equally  occurs  in  the  juice  of  our 
Milkweeds  or  Silkweeds.  Gutta-Percha  is  a  similar  product  of  the 
milky  juice  of  a  Sapotaceous  tree  of  Borneo. 

89.  The  quaternary  class  of  products  (viz.  those  which  consist  of 
the  four  elements,  carbon,  hydrogen,  oxygen,  and  nitrogen,  79)  are 
of  two  kinds,  the  special  and  the  general.  The  former  are  peculiar 
to  certain  plants  ;  the  latter  are  universal  products  of  vegetation. 
Examples  of  the  special  kind  are  found  in  Hydrocyanic  or  Prussic 
Acid,  already  mentioned  (86),  and  the 

90.  Alkaloids,  such  as  Morphine,  Strychnine,  and  Quinine.  These 
are  principally  formed  in  the  bark  and  the  leaves.  We  do  not  know 
that  they  bear  any  part  in  vegetation,  nor  of  what  use  they  are  to 
the  plant.  In  these  substances  reside  the  most  energetic  properties 
of  the  vegetable,  considered  as  to  its  action  on  the  animal  economy, 
the  most  powerful  medicines,  and  the  most  virulent  poisons.  That 
they  are  of  the  nature  of  excretions  may  be  inferred  from  the  fact, 
that  a  plant  may  be  poisoned  by  its  own  products,  introduced  into  its 
ascending  sap. 

91.  The  principal  general  quaternary  product  of  plants  is  Pro- 
teine,  the  nature  and  uses  of  which  have  already  been  explained 
(27,  79).     As   it   exists   in   living  cells   in  a  liquid  or  gelatinous 


58  THE    ELEMENTARY    STRUCTURE    OF    PLANTS. 

state,  it  receives  the  name  of  ])rotopIasm.  Besides  lining  the  walls 
of  living  cells  and  forming  the  nucleus,  it  is  also  a  component  of  one 
of  the  most  important  vegetable  products,  viz. 

92.  Chlorophyll,  or,  as  the  name  denotes,  Leaf-green,  the  substance 
which  gives  the  universal  green  color  to  the  leaves  and  herbage. 
This  is  formed  principally  in  parts  exposed  to  the  light,  such  as  the 
green  bark,  and  especially  the  leaves.  It  generally  occurs  in  the 
form  of  minute  soft  granules,  either  separate  or  in  clusters,  which 
lie  free  in  the  cells  (Fig.  71),  or  adhere  loosely  to  their  sides.  In 
some  common  Conferva?  the  chlorophyll  takes  the  form  of  rows  of 
granules,  or  of  continuous  bands,  often  spiral  in  form.  The  exact 
composition  of  chlorophyll  is  still  unknown.  The  green  coloring 
matter  makes  only  a  small  part  of  the  bulk  of  the  grains.  It  may 
be  dissolved  out  by  alcohol  or  ether,  leaving  a  colorless  mass,  which, 
as  it  is  turned  yellow  by  iodine,  evidently  contains  nitrogen.  The 
green  matter  is  found  to  consist  partly  of  wax,  and  partly  of  a  pecu- 
liar quaternary  substance  allied  to  indigo. 

93.  Earthy  Incrustations.  As  the  roots  naturally  take  in  some 
earthy  matters,  dissolved  in  the  water  they  absorb  from  the  soil, 
these  necessarily  accumulate  in  the  cells  of  the  plant.  The  siliceous 
and  calcareous  matters,  being  very  sparingly  soluble,  are  usually 
deposited  on  the  Avails  of  the  cells  as  an  incrusting  lining,  or  else 
are  incorporated  into  its  substance  along  with  the  organic  thickening 
deposit  (41).  This  earthy  part  of  vegetable  fabric  may  be  brought 
to  vieAV  by  carefully  burning  a  piece  of  a  leaf  or  any  other  organ,  — 
which  decomposes  and  drives  off  all  the  vegetable  matter,  —  and  then 
examining  the  ashes  by  the  microscope.  These  are  mineral  matter, 
and  when  undisturbed  they  will  be  found  to  have  copied  the  shape 
and  all  the  minute  markings  of  the  cells,  like  casts.  In  the  Diato- 
macea?,  —  a  family  of  microscopic  and  ambiguous  plants  of  the  sim- 
plest structure,  —  a  great  part  of  the  thickness  of  the  cell-wall  is 
silex,  and  consequently  indestructible  by  decay.  So  that  the  forms 
of  these  minute  organisms  are  preserved  indefinitely,  after  the  de- 
composition of  the  organic  structure ;  their  silicious  remains  accu- 
mulating at  the  bottom  of  the  water  in  which  they  lived,  to  such 
extent  as  to  produce  immense  strata  in  many  places,  their  forms  and 
markings  so  perfectly  preserved  for  ages  that  the  species  may  be 
nearly  as  well  characterized  from  these  casts  as  from  living  indi- 
viduals. Earthy  matters  also  occur  in  the  cells  of  plants  in  the 
form  of  microscopic 


CRYSTALS    OR   RAPHIDES. 


59 


94.  Crystals,  or  Rapllides  (Fig.  71-78).  These  exist  in  more  or 
less  abundance  in  almost  every  plant,  especially  in  the  cells  of  the 
bark  and  leaves,  as  well  as  in  the  wood  and  pith  of  herbaceous 
plants.  In  an  old  stem  of  the  Old-man  Cactus  (Cereus  senilis),  the 
enormous  quantity  of  eighty  per  cent  of  the  solid  matter  left  after 
the  water  was  driven  off  was  found  to  consist  of  these  crystals.  In 
the  thin  inner  layers  of  the  bark  of  the  Locust,  each  cell  contains  a 
single  crystal,  as  is  shown  in  Fig.  75.  Professor  Bailey,  who  has  de- 
voted particular  attention  to  this  subject,  computed  that,  in  a  square 
inch  of  a  piece  of  Locust-bark,  no  thicker  than  ordinary  writing-paper, 
there  are  more  than  a  million  and  a  half  of  these  crystals.  There 
is  frequently  a  group  of  separate  crystals  in  the  same  cell,  or  a  con- 
glomerate cluster,  as  in  Fig.  76.  The  most  common  form  is  that 
of  a  long  and  narrow  four-sided  prism,  so  slender  that  it  resembles 
a  needle  (Fig.  71-73).  Such  crystals  were  accordingly  called 
Raphides,  i.  e.  needle-shaped  bodies,  —  a  name  which  has  been  ex- 
tended to  include  all  crystals  in  plants,  of  whatever  shape.  When 
the  crystals  are  needle-shaped,  they  usually  occur  in  large  numbers 
in  each  crystal-bearing  cell,  packed  together  in  a  bundle.     These 


FIG.  71.  Raphides,  or  acicular  crystals,  from  the  stalk  of  the  Rhuharb  :  three  of  the  cells 
contain  chlorophyll,  and  two  of  them  raphides. 

FIG.  72.  Raphides  of  an  Arum,  contained  in  a  large  cell ;  and  73,  the  same,  detached  from 
the  surrounding  tissue,  and  discharging  its  contents  upon  the  application  of  water. 

FIG.  74.     Crystals  from  the  base  of  an  onion,  one  of  them  a  hemitrope  or  double. 

FIG.  75.     Crystals  of  the  inner  bark  of  the  Locust. 

FIG.  76.    A  glomerate  mass  of  crystals  from  the  Beet-root. 

FIG.  77,  78.  Crystals  from  the  bark  of  Hickory.  Figures  73-78,  and  also  69,  are  from 
sketches  kindly  supplied  by  the  late  Professor  Bailey  of  West  Point. 


60  THE  GENERAL  DEVELOPMENT  OF  PLANTS. 

may  be  readily  found  in  the  stalks  of  the  Rhubai-b,  the  Four-o'clock, 
the  Arum  or  Indian  Turnip,  and  the  Calla.  In  the  latter  plants,  a 
crystal-bearing  cell  in  the  leaf  may  often  be  detached  entire  from 
the  surrounding  tissue :  when  moistened,  it  absorbs  water  by  endos- 
mosis,  becomes  distended,  and  may  sometimes  be  seen  to  eject  its 
crystals  one  by  one,  in  a  curious  manner,  through  a  minute  perfora- 
tion at  one  or  both  ends  (Fig.  73).  As  to  their  composition,  these 
crystals  more  commonly  consist  of  oxalate  of  lime ;  but  those  of  car- 
bonate, sulphate,  or  phosphate  of  lime  are  not  unfrequent. 

95.  Cystolitlies  are  a  peculiar  structure  composed  of  crystalline 
mineral  and  of  vegetable  matter  combined,  of  common  occurrence  in 
the  leaves  of  the  Fig,  Hop,  Mulberry,  and  all  the  Nettle  family, 
just  beneath  the  epidermis.  They  are  globular  or  club-shaped 
bodies,  or  of  various  other  forms,  usually  hanging  by  a  short  stalk 
in  an  enlarged  cell :  their  principal  mass  is  found  to  be  cellulose ; 
but  their  surface  is  studded  with  crystalline  points  of  carbonate  of 
lime. 


CHAPTER     II. 

OF  THE  GENERAL  DEVELOPMENT  AND  MORPHOLOGY  OF  PLANTS. 

96.  Having  ascertained  what  vegetable  fabric  consists  of,  Ave  are 
prepared  to  consider  how  these  organic  materials,  the  cells,  are  com- 
bined to  constitute  a  vegetable,  what  the  parts  or  organs  of  plants 
are,  how  they  are  related  to  each  other,  and  how  they  live,  grow, 
and  perform  the  work  of  vegetation.  Viewing  plants  as  individual 
beings,  we  may  now  proceed  to  study  their  Organography  or  Mor- 
phology (3). 

97.  Plants  occur  under  the  greatest  diversity  of  forms.  Some 
kinds  are  of  the  utmost  simplicity ;  and  many  of  these  are  so  minute, 
that  separately  they  are  invisible  to  the  naked  eye,  and  become 
apparent  only  by  their  aggregation  in  vast  numbers.  Others  are 
highly  complex  in  structure,  and  may  attain  a  great  size,  such  as 
gigantic  trees,  some  of  which  have  flourished  for  a  thousand  years 
or  more.  But  each  plant  or  tree,  however  vast  or  complex  it  may 
become,  commenced  its  existence  as  a  single  vegetable  cell,  by  the 


PLANTS    OF   THE    LOWER   GRADE.  61 

multiplication  of  which  the  whole  fabric  was  built  up.  All  our  or- 
dinary herbs  and  trees,  however,  even  while  in  the  seed,  have  already 
passed  beyond  this  stage,  and  consist  at  this  time  of  a  mass  of  cells, 
more  or  less  distinctly  wrought  into  the  form  of  a  plantlet ;  while 
the  germs  of  plants  of  a  lower  grade,  at  the  time  of  their  separation 
from  the  parent  plant,  are  each  no  more  than  a  single  cell.  Cells  of 
this  kind,  destined  to  give  rise  to  new  individuals  (i.  e.  for  reproduc- 
tion), are  called  Spores.  The  name  spore  is  from  a  Greek  Avord, 
meaning  the  same  as  seed. 

98.  Plants  may  be  distinguished,  therefore,  into  two  great  Series 
or  Grades,  a  lower  and  a  higher ;  —  the  lower  or  simpler  grade  con- 
sisting of  those  plants  which  directly  spring  from  single  cells  or 
spores  ;  the  higher  grade,  of  those  which  spring  from  seeds. 


Sect.  I.     Plants  of  the   Lower   Grade;   their   Develop- 
ment from  the  Cell. 

99.  This  grade  includes  the  simplest  and  minutest  plants,  and 
also  many  which  attain  a  great  size,  and  exhibit  no  small  complexity 
of  structure,  such  as  Tree  Ferns  (Fig.  100),  for  instance.  The 
very  lowest  kinds  not  only  begin  their  existence  as  single  cells,  but 
continue  so  throughout  their  whole  growth.  The  most  simple  possi- 
ble form  of  vegetation  therefore  consists  of 

100.  Plants  of  a  Single  Cell.  In  these  minims  of  the  vegetable 
world,  the  plant  is  reduced  to  its  lowest  terms :  the  plant  and  the 
cell  are  here  identical.  The  cell  constitutes  an  entire  vegetable  wiih- 
out  organs,  imbibing  its  food  by  endosmosis  (40)  through  its  walls, 
assimilating  this  food  in  its  interior,  and  converting  the  organizable 
products  at  first  into  the  materials  of  its  own  enlargement  or  growth, 
and  finally  into  new  cells,  which  constitute  its  progeny.  Thus  we 
have  an  epitome  of  all  that  is  essential  in  vegetation,  even  on  the 
largest  scale ;  namely,  the  imbibition  of  inorganic  materials  ;  their 
assimilation;  their  application  to  the  growth  of  the  individual,  or 
nutrition;  and  the  formation  of  new  individuals,  or  reproduction. 
Every  stream  or  pool  of  water  abounds  with  such  plants,  often  in 
great  variety.  Simple  as  these  plants  are,  they  are  by  no  means 
restricted  to  one  monotonous  pattern :  perhaps  they  present  as  great 
diversity  of  form  as  do  the  kinds  of  ordinary  vegetation,  although 
from  their  minuteness  they  are  mostly  invisible  to  the  naked  eye. 

6 


62  THE  GENERAL  DEVELOPMENT  OF  PLANTS, 

The  admirable  memoirs  of  Nageli  and  of  Braun  upon  One-celled 
Plants,  and  the  works  of  Ralfs,  Kutzing,  Thwaites,  &c.  upon  the 
Desmidiaceae  and  Diatomacea?,  illustrate  a  great  variety  of  forms. 
The  simplest  possible  case  is  that  of 

101.  Plants  of  a  Single  Globular  Cell ; 
that  is,  of  a  cell  which  grows  equally  in 
^|-,®  ®  ^iJP  (J|||i  every  direction,  and  therefore  retains  the 
original  form.  The  microscopic  plant 
known  as  giving  rise  to  the  phenomenon 
of  red  snoio  furnishes  a  good  illustration 
of  the  kind  (Fig.  79,  80)  :  and  so  does  a 
more  common  species,  Protococcus  cru- 
entus,  which  forms  dull-crimson  patches,  resembling  blood-stains,  on 
the  northern  side  of  damp  rocks  or  old  walls.  Each  sphere  is  a 
single  cell,  which,  quickly  attaining  its  growth,  produces  (probably 
by  division  of  the  contents)  a  number  of  free  cells  in  its  interior. 
These  escape  by  the  decay  of  the  walls  of  the  mother-cell,  grow 
speedily  into  similar  cells  or  plants  themselves,  giving  rise  to  another 
generation,  and  perish  in  their  turn.  Fig.  81  represents  another 
and  similar  one-celled  plant ;  and  Fig.  82  and  83  show  its  mode  of 
propagation,  namely,  by  division  of  the  whole  living  contents  into 
two  portions,  and  these  again  into  two,  these  four  globular  masses 
soon  acquiring  a  wall  of  cellulose,  and  becoming  so  many  distinct 
cells  or  plants ;  —  the  whole  process  admirably  illustrating  a  com- 
mon mode  of  cell-multiplication  (3G).  Indeed,  another  microscopic 
plant  of  the  kind,  very  common  in  shallow  pools  at  the  beginning  of 
spring,  was  taken  as  the  readiest  example  of  this  multiplication  of 
cells  (Fig.  18-22).  This  propagation  causes  the  destruction  of  the 
mother-plant  in  each  generation,  all  its  living  contents  being  em- 
ployed in  the  formation  of  the  progeny,  and  its  effete  wall  obliter- 
ated by  softening  or  decay,  and  by  the  enlargement  of  the  contained 
cells.  Thus  the  simplest  vegetation  goes  on,  from  generation  to 
generation.  The  softened  remains  of  the  older  cells  often  accumu- 
late and  form  a  gelatinous  stratum  or  nidus,  in  which  the  succeeding 
generations  are  developed,  and  from  which  they  doubtless  derive  a 

FIG.  79.  Several  individuals  of  the  Red-Snow  Plant  (Protococcus  nivalis)  magnified.  80. 
An  individual  highly  magnified,  showing  more  distinctly  the  new  cells  or  spores  formed  with- 
in it. 

FIG.  81.  An  individual  of  Chroococcus  rufescens,  after  Nageli,  much  magnified.  82.  A 
more  advanced  individual,  with  the  contents  forming  two  new  cells  by  division.  83.  Another, 
with  the  contents  divided  into  four  new  cells. 


OF   THE    LOWER    GRADE. 


63 


part  of  their  sustenance, — just  as  a  tufted  Moss  is  nourished  in  part 
from  the  underlying  bed  of  vegetable  mould  which  is  formed  of  the 
decayed  remains  of  its  earlier  growth.  Other  one-celled  plants 
enlarge  in  one  direction  more  than  in  any  other,  so  becoming  oval 
or  oblong,  and  making  a  transition  to  a  somewhat  higher  grade  of 
vegetation,  viz. 

102.  Plants  of  a  Single  Elongated  Cell.  Such  plants  may  be  con- 
ceived to  bear  the  same  relation  to  the  foregoing,  that  ducts  (57) 
and  wood-cells  (53)  do  to  cells  of  parenchyma  (51).  For  an  ex- 
ample we  may  take  any  species  of  Oscillaria 

(Fig.  84)  ;  a  form  of  aquatic  vegetation  of  mi- 
croscopic minuteness,  considered  as  to  the  size 
of  the  individuals  ;  but  these  rapidly  multiply 
in  such  inconceivable  numbers,  that,  at  certain 
seasons,  they  sometimes  color  the  surface  of 
whole  lakes  of  a  green  hue,  as  suddenly  as 
broad  tracts  of  alpine  or  arctic  snow  are  red- 
dened by  the  Red-Snow  Plant.  If  the  trans- 
verse markings  of  some  Oscillarias  answer  to 
internal  partitions,  then  they  make  a  transition 
between  one-celled  plants  and  those  formed  of 
a  row  of  cells.  —  Since  cells  which  form  part  of 
the  fabric  of  vegetables  are  sometimes  branched 
(38),  we  should  naturally  expect  to  find,  as  the 
next  step  in  the  development, 

103.  Plants  of  an  Elongated  and  Branching  Cell.  Good  ex- 
amples of  the  sort  are  furnished  by  the  species  of  Yaucheria,  which 
form  one  kind  of  the  delicate  and  flossy  green  threads  abounding  in 
fresh  waters,  and  known  in  some  places  by  the  name  of  Brook-silk. 
These,  under  the  magnifying-glass,  are  seen  to  be  single  cells,  of 
unbroken  calibre,  furnished  here  and  there  with  branches  (Fig.  89). 
The  branches  are  protrusions,  or  new  growing  points,  which  shoot 
forth  by  a  sort  of  budding,  and  have  the  power  of  continuous  growth 
from  the  apex.  In  Bryopsis  (Fig.  91),  a  beautiful  small  Sea-weed, 
the  branches  are  much  more  numerous  and  regularly  arranged; 
their  cavity  is  continuous  with  that  of  the  main  stem,  if  we  may 
so  call  it :  in  other  words,  the  whole  plant,  which  is  by  no  means 
minute,  consists  of  a  single,  repeatedly  many-branched  cell.  And 
in  Codium,  another  genus  of  marine  Alga?,  we  have  an  indefinitely 

FIG.  84.    Two  individuals  of  Oscillaria  spiralis,  magnified  ;  one  with  an  extremity  cut  off. 


64 


THE  GENERAL  DEVELOPMENT  OF  PLANTS, 


ramified  cell,  intricately  interlaced  or  compacted,  and  forming  dense 
masses  of  considerable  size  and  of  definite  shapes. 


104.  While  in  these  cases  the  ramifications  of  the  cell  imitate,  or 
as  it  were  foreshadow,  the  stem  and  branches  of  higher  organized 
plants,  we  have  in  Botrydiurn  (Fig.  88)  a  cell  whose  ramifications 
resemble  and  perform  the  functions  of  a  root.  This  consists  of  an 
enlarged  cell,  which  elongates  and  ramifies  downwards,  the  slender 
branches  penetrating  the  loose  and  damp  soil  on  which  the  plant  grows, 
exactly  in  the  manner  of  a  subdivided  root.  Meanwhile,  a  crop  of 
spores  or  rudimentaiy  new  cells  is  produced,  by  original  cell-forma- 
tion (29),  in  the  liquid  contents  of  the  mother-cell:  these,  escaping 
when  that  decays  or  bursts,  grow  into  similar  plants,  in  the  manner 
shown  by  Fig.  86,  87.  The  spores  by  which  Vaucheria  is  propagated 
originate  in  a  somewhat  different  way.  When  about  to  fructify,  the 
apex  of  a  branch  enlarges,  its  green  contents  thicken,  separate  from 
those  below,  condense  into  a  rounded  mass,  which  acquires  a  coat  of 
protoplasm  (Fig.  89,  a)  :  the  sac  in  which  it  was  formed  soon  bursts 
open,  and  the  new-born  spore  escapes  into  the  water  (Fig.  90).  It 
moves  about  freely  for  some  hours  (678),  when  a  coat  of  cellulose  is 
formed  upon  its  surface,  converting  it  into  a  true  cell,  which  soon 


FIG.  85  - 87.  Botrydiurn  Wallrothii  in  its  development,  and  with  new  cells  forming  within : 
after  Kiitzing:  85.  the  cell  still  spherical:  8G,  pointing  into  a  tube  below:  87,  the  tube  pro- 
longed and  branched  :  all  much  magnified. 

FIG.  88.     Botrydiurn  argillaceum,  after  Endlicher  ;  the  full-grown  plant,  magnified. 

FIG.  89.  Vaucheria  clavata,  enlarged  :  a,  a  spore  formed  in  the  enlarged  apex  of  that 
branch.    90.  End  of  the  branch,  more  magnified,  with  the  spore  escaped  from  the  burst  apex. 

FIG.  91.    Bryopsis  plumosa  ;  summit  of  a  stem  with  its  branchlets,  much  enlarged. 


OF    TUB    LOWER    GRADE. 


65 


grows  by  elongating  into  a  thread,  one  end  of  which  fixes  itself  to  a 
stone  or  some  other  solid  body,  while  the  other  grows  first  into  a 
simple  tube,  and  then  sends  off  branches  like  its  parent.  In  this 
way,  a  plant  composed  of  a  single  cell  imitates  not  obscurely  the 
upward  and  downward  growth  (the  root  and  the  stem)  of  the  more 
perfect  plants,  or  when  cells  like  these,  whether  simple  or  branched, 
form  cross-partitions  as  they  grow,  in  the  manner  of  the  Conferva 
(Fig.  15)  used  to  illustrate  this  mode  of  cell-multiplication,  they  give 
rise  to 

105.  Plants  of  a  Single  ROW  of  Cells.  Most  of  the  thread-like  green 
Algoa  (Conferveaj),  which  abound  in  pools  and  brooks,  are  of  this 
sort.  So  are  the 
Moulds  or  Mildew 
Fungi,  of  which 
three  kinds  are  here 
represented ;  viz. 
the  Bread-Mould 
(  Fig.  92 ),  and 
the  Cheese-Mould 
(Fig.  93),  which 
live  upon  dead  or- 
ganic matter ;  and 
a  species  of  Botrytis  (Fig.  94).  The  latter,  and  other  Moulds  of 
the  same  or  of  other  kinds,  feed  upon  the  juices  of  living  plants,  and 
even  animals,  where  they  commit  great  ravages.  The  too  well- 
known  potato-disease,  for  example,  is  probably  caused  by  the  attack 
of  a  species  of  Botrytis ;  a  similar  species  has  long  been  known  as 
the  cause  of  the  muscardine,  a  fatal  malady  of  silk-worms,  and  the 
malady  which  has  for  several  years  destroyed  a  great  part  of  the 
grape-crop  in  Europe  is  caused  by  another  parasitic  plant  of  the 
same  simple  structure.  The  accompanying  figures  show  only  the 
perfect  state  of  these  troublesome  little  plants,  or  rather  their  fructi- 
fication. Their  vegetation  consists  of  long  and  branching  threads 
(of  which  a  small  portion  only  is  represented  at  the  base),  which 
penetrate  and  spread  widely  and  rapidly  through  the  vegetable,  or 
other  body  they  live  on,  and  feed  upon  its  juices.  At  length  they 
break  out   upon   the    surface,  and   produce  countless   numbers  of 


FIG.  92-94.  Three  kinds  of  Mould,  magnified.  92.  The  Bread-Mould  (Mucor,  or  Asco- 
phora).  93.  The  Cheese-Mould  (Aspergillus  glaucus).  94.  Botrytis  Bassiaua,  the  species 
which  attacks  silk-worms,  &c. 

G* 


66 


THE  GENERAL  DEVELOPMENT  OF  PLANTS, 


spores  (97),  or  minute  rudimentary  cells,  which  are  detached  from 
the  parent  plant  and  serve  the  purpose  of  seeds.  The  spores  are 
in  some  cases  produced  (probably  by  original  cell-formation),  in  an 
enlarged  terminal  cell,  as  in  the  Bread-Mould  (Fig.  92)  ;  while  in 
other  cases  they  are  naked,  and  arise  from  cell-division,  as  in  Fig. 
93,  94. 

106.  Plants  of  this  simple  structure  (belonging  chiefly  to  the 
lower  Alga?  and  Fungi)  are  almost  as  various  in  form  and  numerous 
in  species  as  are  the  higher  kinds  of  vegetation.  Some  consist  of  a 
single  jointed  thread ;  others  are  excessively  branched ;  and  some- 
times the  branches  are  interlaced  or  compacted  to  form  masses  or 
strata  of  considerable  size.  Some  of  them  present  little  or  no  dis- 
tinction among  the  cells  they  consist  of,  each  cell  performing  the 
same  office  as  any  other,  and  each  capable  of  producing  spores  or  in 
Some  way  serving  for  reproduction ;  such  may  well  be  regarded 
as  rows  of  one-celled  plants,  more  or  less  united.  But  more  com- 
monly, even  in  the  simplest  vegetable  forms,  the  work  which  the 
plant  has  to  perform  is  divided,  some  parts  serving  for  vegetation  or 
nutrition,  and  others  for  reproduction,  as  we  see  is  the  case  with  the 
Moulds,  &c.  Even  a  one-celled  plant  may  begin  to  have  organs,  or 
parts  adapted  to  special  purposes,  as  is  well  shown  by  Botrydium 
and  Vaucheria  (Fig.  85-90).  As  we  ascend  in  the  scale  of  vege- 
table life,  more  and  more  specialization  will  be  found  at  every  step. 

107.  A  slight  change  in  the  Avay  the  cells  multiply,  namely,  the 
formation  of  partitions  in  two  directions  instead  of  only  one,  intro- 
duces the  next  advance  in  vegetable  development,  giving  rise  to 


0o£ 

pWm 
Mb 


tlS 


108.  Plants  of  a  Single  Plane  or  Layer  of  Cells.    Figures  18-22  show 

how  a  plant  of  a  single  spherical  cell  may  multiply,  by  repeated 


FIG.  95.  A  piece  of  Delesseria  Leprieurei,  from  Hudson  River,  of  twice  the  natural  size. 
96.  A  portion  of  the  whole  breadth  of  the  same,  more  magnified,  to  show  the  cellular  struc- 
ture. The  cells  have  thick  gelatinous  walls ;  those  iu  the  middle  are  elongated,  those  towards 
the  margins  rounded.     97.  A  small  portion  still  more  magnified. 


OF    THE    LOWER    GRADE.  G7 

division,  into  two,  four,  and  sixteen  such  plants,  and  so  on.  But  if 
these  cells  had  merely  remained  in  connection  as  they  multiplied, 
they  would  have  composed  one  plant,  consisting  of  a  stratum  of  cells. 
This  is  just  what  we  have  in  the  Dulse  or  Laver  (Ulva,  &c.)  and 
some  other  simple  leaf-like  Alga?  of  various  kinds,  such,  for  example, 
as  that  illustrated  in  Fig.  95  -  97.  When  the  whole  body  of  a  plant 
is  thus  expanded  and  leaf-like,  it  forms  what  is  called  a  Frond. 

108°.  Not  only  Sea-weeds,  but  many  Liverworts  and  Lichens, 
grow  in  this  way.  (In  Lichens,  &c,  the  expanded  body  usually 
takes  the  name  of  Thallus.)  In  most  cases,  however,  such  plants 
are  composed  of  more  than  one  layer  of  cells,  or  of  a  considerable 
number  of  layers.  And  those  of  thread-like  forms,  resembling  naked 
stems  and  branches,  in  all  the  coarser  and  in  some  very  delicate 
kinds,  are  made  up,  like  the  parts  of  ordinary  vegetables,  of  several 
thicknesses  of  cells  ;  that  is,  they  are 

109.  Plants  of  a  Solid  Tissue  Of  Cells,  formed  by  cell-multiplication 
through  division  taking  place  in  more  than  two  directions.  Sea- 
weeds, Lichens,  and  other  plants  of  the  lowest  orders,  forming  in 
this  way  a  tissue  of  cells,  generally  exhibit  either  leaf-like  or  stem- 
like shapes,  but  seldom  if  ever  do  they  present  both  in  the  same 
plant.  They  may  resemble  leaves,  or  they  may  resemble  stem  and 
branches,  or  display  a  variety  of  forms  intermediate  between  stem 
and  leaf.  But  it  is  only  when  Ave  come  to  the  highest  tribe  of 
Liverworts,  and  to  the  true  Mosses,  that  the  familiar  type  of  ordinary 
vegetation  is  realized  in 

110.  Plants  with  a  Distinct  Axis  and  Foliage;  that  is,  with  a  stem 

which  shoots  upward  from  the  soil,  or  whatever  it  is  fixed  to,  or 
creeps  on  its  surface ;  which  grows  onward  from  its  apex,  and  is 
symmetrically  clothed  with  distinct  leaves  as  it  advances.  All  these 
lower  vegetables,  of  Avhatever  form,  imbibe  their  food  through  any 
or  every  part  of  their  surface,  at  least  of  the  freshly  formed  parts. 
Their  roots,  when  they  have  any,  are  usually  intended  to  fix  the 
plant  to  the  rock  or  soil,  rather  than  to  draw  nourishment  from  it. 
The  strong  roots  of  the  Oar-weed,  Devils  Apron  (Laminaria),  and 
other  large  Sea-weeds  of  our  coast,  are  merely  hold-fasts,  or  cords 
expanding  into  a  disc-like  surface  at  the  extremity,  which  by  their 
adhesion  bind  these  large  marine  vegetables  firmly  to  the  rock  on 
which  they  grow.  Mosses  also  take  in  their  nourishment  through 
their  whole  expanded  surface,  principally  therefore  by  their  leaves ; 
but  the  stems  also  shoot  forth  from  time  to  time  delicate  rootlets, 


68 


THE  GENERAL  DEVELOPMENT  OF  PLANTS. 


composed  of  slender  cells  which  grow  in  a  downward  direction,  and 
doubtless  perform  their  part  in  absorbing  moisture.  A  Moss,  there- 
fore, is  like  an  ordinary  herb  in  minia- 
ture, and  exhibits  the  three  general 
Organs  of  Vegetation,  viz.  Root, 
Stem,  and  Leaves. 

ill.    Cellular   and   Vascular   Plants. 

"While  the  Mosses  emulate  ordinary 
herbs  and  trees  in  vegetation  and  ex- 
ternal appearance,  they  accord  with 
the  lowest  kinds  of  plants  in  the  sim- 
plicity of  their  anatomical  structure. 
They  are  entirely  composed  of  cellu- 
lar tissue  strictly  so  called,  chiefly  in 
the  form  of  parenchyma  (51)  ;  at  least 
they  have  no  distinct  vessels  or  ducts 
(57)  and  no  true  wood  in  their  com- 
position. The  Mosses,  along  with  the 
Lichens,  Algae,  Fungi,  &c,  were  there- 
fore denominated  Cellular  Plants 
by  De  Candolle.  All  plants  of  higher 
grade,  inasmuch  as  vascular  and  woody 
tissues  enter  into  their  composition, 
when  they  are  herbs  as  well  as  when 
they  form  shrubs  or  trees,  he  distinguished  by  the  general  name  of 
Vascular  Plants. 

112.  The  strength  which  woody  tissue  imparts  (54)  enables 
plants  in  which  it  abounds  to  attain  a  great  size  and  height ;  while 
Mosses  and  other  cellular  plants  are  of  humble  size,  except  when 
they  live  in  water,  in  which  some  of  the  coarser  Sea-weeds  do  indeed 
acquire  a  prodigious  length.  Although  true  Mosses  have  no  Avood 
in  their  composition,  yet  the  so-called  Club-Mosses  have.  So  also 
have  the  Ferns,  the  highest  organized  family  of  the  lower  grade  of 
plants ;  and  although  these  are  mostly  herbs,  or  else  plants  with 
their  more  or  less  woody  stems  creeping  on  or  beneath  the  surface 
of  the  ground,  yet  in  warm  climates  some  species  rise  with  woody 
trunks  into  tall  and  palm-like  trees.     But  even  these,  like  the  hum- 


FIG.  98.  An  individual  of  a  Moss  (Physcornitrium  pyriforme),  enlarged  to  about  twelve 
times  the  natural  size.  99.  Tip  of  a  leaf,  cut  across,  much  magnified,  to  show  that  it  is  made 
up  (except  the  midrib)  of  a  single  layer  of  cells. 


PLANTS    OF    THE    HIGHER    GRADE. 


69 


blest  Mosses  or  the  minutest  Moulds,  spring  from  single  cells  or 
spores  (97),  and  not  from  true  seeds.  And  the  apparatus  by  which 
these  spores  are  produced,  whatever  be  its  nature,  is  not  a  flower. 
Plants  of  the  lower  grade  (98, 

.  100 

99)   are  therefore   collectively 
denominated 

113.  Flowerlcss   or   Cryptoga- 

niOUS  Plants.  The  first  name 
expresses  the  fact  that  the  or 
gans  of  fructification  in  these 
plants  are  not  of  the  nature 
of  real  flowers.  The  second 
name,  which  Avas  introduced 
by  Linnaeus,  and  is  composed 
of  two  Greek  words  meaning 
"  concealed  fructification,"  re- 
fers to  the  obscure  nature  of 
the  organs  or  the  processes  of 
reproduction  in  these  plants, 
which  have  only  recently  come 
to  be  understood.  Some  ac- 
count of  them  will  be  given 
in  Chapter  XII. 


Sect.  n.     Plants  of  the  Higher  Grade;  their  Develop- 
ment from  the  Seed. 

114.  Flowering  or  Phamogamous  Plants,*  — so  called  in  contradis- 
tinction to  the  Flowerless  or  Cryptogamous,  —  is  the  general  name 
for  the  higher  grade  of  plants,  to  which  our  ordinary  herbs,  shrubs, 
and  trees  belong,  and  which  may  be  said  to  exhibit  the  perfected  type 
of  vegetation.     The  lower  grade  begins  with  plants  so  simple  as  to 


*  Sometimes  written  Phanerogamous.  Both  terms  are  made  from  the  same 
Greek  words,  and  signify,  by  a  metaphorical  expression,  the  counterpart  of 
Cryptogamous ;  that  is,  that  the  essential  organs  of  the  flower  are  manifest  or 
conspicuous. 


FIG.  100.     Sketch  of  a  Tree  Fern,  Dicksonia  arborescens,  of  St.  Helena ;  after  Dr.  J.  D. 
Hooker.     101.  Polypodium  vulgare,  a  common  Fern,  with  its  creeping  stem  or  rootstock. 


70 


DEVELOPMENT    OF    FLOWERING    OR    PIIvENOGAMOUS 


be  destitute  of  organs  ;  and  it  is  only  in  the  higher  Cryptogainous 
plants,  such  as  Mosses  and  Ferns,  that  the  familiar  organs  of  ordi- 
nary vegetation  appear  as  separate  parts  of  the  plant,  viz.  the  root, 
stem,  and  leaves.  In  the  higher  grade  (i.  e.  in  Phsenogamous 
Plants)  these  three  parts  are  well  defined,  and  always  present,  in 
some  form  or  other ;  —  a  few  anomalous  instances  excepted,  such 
as  the  common  Duck-weed,  for  example  (Fig.  102). 
Here  stem  and  leaf  are  as  it  were  blended,  in  the 
manner  of  a  Liverwort,  to  form  a  flat  green  body, 
winch  floats  on  the  water,  exposing  the  upper  sur- 
face like  a  leaf  to  the  -light,  while  one  or  more  roots 
proceed  from  the  lower,  and  a  small  and  simple 
flower  at  length  makes  its  appearance  on  some  part 
of  the  margin.  This  is  an  extremely  simplified 
state  of  a  Pluenogamous  plant. 

115.  Ordinarily,  not  only  are  the  root,  stem,  and 
foliage  distinct  and  separate  from  each  other,  but 
also  distinct  from  the   apparatus  for  reproduction. 
So  that  the  plant  is  composed  of  two  kinds  of  or- 
102  gans,  viz.  Organs  of  Vegetation  and  Organs 

of  Reproduction. 

116.  The  Organs  Of  Vegetation  are  the  Root,  Stem,  and  Leaves  (110). 
These  are  so  called  because  they  are  jointly  concerned  in  the  nutri- 
tion and  growth  of  the  plant,  and  in  the  performance  of  all  its  char- 
acteristic functions,  and  they  are  all  that  is  so  concerned.  Making 
up  as  they  do  the  entire  vegetable,  and  repeated  under  varied  forms 
throughout  its  whole  development,  they  are  also  termed  the  Funda- 
mental Organs  of  plants. 

117.  The  Organs  of  Reproduction  in  the  simplest  Cryptogamous 
plants  are  not  distinct  from  those  of  vegetation ;  but  in  most  plants, 
even  of  the  lowest  families,  the  cells  for  repix>duction  are  different 
in  appearance  and  in  the  mode  of  their  formation  from  those  which 
serve  for  vegetation.  These  reproductive  cells,  or  Spores,  with  the 
apparatus  for  their  production  and  protection,  whatever  it  may  be, 
constitute  the  organs  of  reproduction  in  Cryptogamous  plants.  In 
Phamogamous  plants  the  organs  of  reproduction  are  the  Flower, 
essentially  consisting  of  Stamens  and  Pistils,  and  the  result  of  their 
co-operation  is  the  production  of  Seed. 

118.  A  Seed  is  a  body  produced  by  the  agency  of  a  flower,  which 
contains,  within  one  or  more  coats  or  coverings,  a  ready-formed 


PLANTS    FROM    THE    SEED. 


71 


plantlet  in  a  rudimentary  state.  Flowerless  or  Cryptogamous  plants 
spring  from  spores  or  single  cells,  -which  when  they  germinate  multi- 
ply to  produce  a  tissue  or  an  aggregation  of  cells,  that  at  length 
grows  and  forms  a  plantlet.  But  a  seed  contains  a  plantlet  ready 
formed,  or  a  germ,  which  is  called  an  Embryo.  And  the  history  of 
a  Flowering  or  Phamogamous  plant  naturally  begins  with 

119.  The  Development  of  the  Embryo  from  the  Seed.     The  embryo 

varies  exceedingly  in  size,  shape,  and  appearance  in  different  plants  ; 
but  it  is  constructed  upon  the  same  general  plan  in  all ;  and  the 
development  of  almost  any  plantlet  from  the  seed  will  serve  to  illus- 
trate the  principal  laws  and  processes  of  vegetable  growth.  To 
commence  with  the  study  of  the  seedling  is  the  readiest  way  to  un- 
derstand the  whole  vegetable  structure  and  life. 

120.  The  seeds  of  the  Eed  or  the  Sugar  Maple  furnish  good 
illustrations,  and  they  are  readily  met  with  in  germination,  i.  e.  just 
developing  the  embryo  into  a  plant.  Also  they  are  large  enough  to 
allow  the  embryo  to  be  extracted  from  the  seed-coats,  and  inspected 
by  the  naked  eye,  or  by  the  aid  of  a  common  hand-glass.  (Fig. 
103-105.)         Here 

the  whole  contents 
of  the  seed  consist 
of  an  embryo,  neatly 
coiled  up  within  the 
seed-coats.       If    un- 

IU3  '"•■  *— 

folded,    or,   which    is 

better,  if  examined  when  just  unfolding  itself  in  germination,  it  is 
seen  to  consist  of  a  tiny  stem  or  axis  (Fig.  104,  105,  a),  bear- 
ing a  pair  of  small  leaves  on  its  summit.  The  axis  is  called  the 
Radicle,  because  it  was  supposed  to  be  the  root ;  though  it  is  really 
the  rudiment  of  the  stem  rather  than  of  the  root,  and  therefore  were 
better  named  the  Caulicle ;  but  the  former  name  is  now  too  well 
established  to  be  superseded.  The  two  little  seed-leaves  (b,  b)  are 
technically  called  Cotyledons  :  and  a  little  bud  which  will  pres- 
ently appear  between  them  (Fig.  106,  c),  or  may  be  discerned  there 
in  many  embryos  before  germination  (as  in  the  Almond,  Fig. 
108,  a)  is  named  the  Plumule.  The  embryo,  accordingly,  is  a 
short  axis  or  stem  bearing  upon  one  end  some  rudimentary  leaves  ; 


FIG.  103.  Embryo  of  Sugar-Maple  as  coiled  up  in  the  seed.  104, 105.  The  same,  just  be- 
ginning to  unfold  and  develop  in  germination  :  a,  the  radicle,  or  primary  stem :  b,  b,  the 
cotyledons  or  seed-leaves. 


72 


DEVELOPMENT    OF    FLOWERING    OB    PHiENOGAMOUS 


or,  in  other  words,  it  is  a  primary  stem  crowned  with  a  leaf-bud. 
When  it  grows,  this  stem  elongates  throughout  its  whole  length,  so 
as  usually  to  raise  the  budding  apex  above  the  surface  of  the  soil, 
into  the  light  and  air,  Avhere  its  cotyledons  expand  into  leaves ;  and 

at  the  same  time  from  the  opposite  ex- 
tremity is  formed  the  root,  which  grows 
in  a  downward  direction,  so  as  to  pen- 
etrate more  and  more  into  the  soil.  The 
two  extremities  of  the  embryo  are  dif- 
ferently organized,  are  differently  affect- 
ed by  light  and  air,  and  grow  in  opposite 
directions.  The  budding  end  invaria- 
bly turns  towards  the  light,  and  grows 
upwards  into  the  air ;  the  root-end  turns 
constantly  from  the  light,  and  buries  it- 
self in  the  dark  and  moist  soil.  These 
tendencies  are  absolute  and  irreversible. 
If  the  budding  end  happen  to  he  point- 
ing downwards  and  the  root  end  up- 
105  wards,  both  will  curve  quite  round  as 

they  grow  to  .assume  their  appropriate  positions.  If  obstacles  inter- 
vene, the  root  will  take  as  nearly  a  downward,  and  the  stem  as 
nearly  an  upward  direction,  as  possible.  These  are  only  the  first 
manifestations  of  an  inherent  property,  which  continues,  with  only 
incidental  modifications,  throughout  the  whole  growth  of  the  plant, 
although,  like  instinct  in  the*  higher  animals,  it  is  strongest  at  the 
commencement :  and  it  insures  that  each  part  of  the  plant  shall  be 
developed  in  the  medium  in  which  it  is  designed  to  live  and  act,  — 
the  root  in  the  earth,  and  the  stem  and  leaves  in  the  air.  The 
plantlet,  therefore,  possesses  a  kind  of  polarity ;  it  is  composed  of 
two  counterpart  systems,  namely,  a  Descending  Axis,  or  root,  and  an 
Ascending  Axis,  or  stem.  The  point  of  union  or  base  of  the  two 
has  been  termed  the  crown,  neck,  or  collar.  Both  the  root  and  stem 
branch ;  but  the  branches  are  repetitions  of  the  axis  from  which 
they  spring,  and  obey  its  laws  ;  the  branches  of  the  root  tending 
to  descend,  and  those  of  the  stem  to  ascend. 


FIG.  106.  A  germinating  embryo  of  Sugar-Maple,  more  advanced :  a,  the  radicle  elongated 
into  the  first  joint  of  stem,  bearing  the  unfolded  cotyledons  or  seed-leaves,  6,  and  between 
them  the  plumule  (c),  or  rudiments  of  the  next  pair  of  leaves  ;  while  from  its  lower  extremity 
the  root,  d,  is  formed. 


PLANTS  FROM  THE  SEED. 


73 


121.  The  root  and  the  stem  grow  not  only  in  opposite  directions, 
but  in  a  different  mode.  The  little  stem,  pre-existing  in  the  seed, 
grows  throughout  its  whole  length,  (but  most  in  its  upper  part,) 
so  that  a  radicle  of  perhaps  less  than  a  line  in  length  may  become  a 
stemlet  two  or  three  inches  long.  It  is  by  this  elongation  that  the 
seed-leaves  are  raised  out  of  the  soil,  so  as  to  expand  in  the  light 
and  air.  Meanwhile  a  root  begins  to  be  formed  at  the  other  end  of 
the  radicle ;  and  this  lengthens  by  continued  cell-multiplication  mainly 
at  its  lower  extremity,  the  parts  once  formed  scarcely  if  at  all  elon- 
gating afterwards  ;  but  the  growth  takes  place  continuously  at  the  tip 
alone.  The  primary  stem,  bearing  the  pair  of  seed-leaves,  soon 
completes  its  development,  and  ceases  to  lengthen.  Then,  if  not 
before,  the  plumule  (Fig.  106,  c)  begins  its  growth  and  develops 
into  a  second  stemlet  on  the  summit  of 
the  first,  bearing  its  pair  of  leaves.  It 
lengthens  in  the  manner  its  predeces- 
sor did,  and  carries  up  the  second  pair 
of  leaves  to  some  distance  above  the 
first ;  then  from  between  them  springs 
a  third  joint  of  stem,  crowned  with  its 
pair  of  leaves  (Fig.  107)  ;  and  so  on, 
building  up  the  whole  herb  or  tree  by 
this  succession  of  similar  growths  or 
joints  of  stem.  The  root,  on  the  other 
hand,  grows  on  in  a  downward  direc- 
tion continuously,  is  not  composed  of  a 
series  of  joints,  and  bears  no  leaves  or 
other  organs. 

122.  The  youngest  seedling  is  there- 
fore provided  with  all  the  organs  of 
vegetation  that  the  full-grown  plant 
possesses ;  and  even  the  embryo  in 
the  seed  is  already  a  miniature  vege- 
table. It  has  a  stem,  from  the  lower 
end  of  which  it  strikes  root  in  ger- 
mination ;  it  has  leaves,  and  it  has  or 

soon  forms  a  bud,  which  develops  into  new  joints  of  stem  bearing 
additional  leaves,  while  beneath  it  sends  its  root  deeper  and  deeper 


FTG.  107.    A  seedling  Maple  which  has  developed  two  additional  joints  of  stem,  each  with 
their  pair  of  leaves. 


74 


DEVELOPMENT    OF   FLOWERING    OR    PH^ENOGAMOUS 


into  the  soil.  The  root  absorbs  materials  for  the  plant's  nourish- 
ment from  the  soil;  these  are  conveyed  through  the  stem  into  the 
leaves,  and  there  assimilated  (12,  15),  under  the  influence  of  the 
light  of  the  sun  and  the  air,  into  organic  matters  which  serve  directly 
for  further  growth,  and  form  the  fabric  of  new  portions  of  stem,  new 
leaves,  and  new  roots,  the  vegetable  thus  increasing  its  size  and  its 
power  at  every  step. 

123.  Once  established,  therefore,  the  plant  can  provide  for  itself, 
drawing  the  needful  materials  from  the  earth  and  the  air,  and 
assimilating  or  organizing  them  by  its  own 
peculiar  power.  But  at  the  beginning,  and 
until  it  has  sent  forth  its  root  into  the  soil 
and  spread  out  its  first  leaves  in  the  light, 
it  must  be  nourished  and  grow  by  means  of 
organized  matter  supplied  by  the  parent 
plant.     This  supply  in  the  Maple  was  de- 


posited in  the  seed-leaves  of  the  embryo,  and  was  barely  sufficient 
to  develop  the  radicle  into  a  tiny  stem,  to  form  a  simple  root  at 
the  lower  extremity,  and  above  to  expand  in  the  light  the  pair 
of  small,  green  seed-leaves  ;  when  the  plantlet  is  left  to  its  own 
resources.  Very  commonly  a  larger  store  of  nourishment  is  pro- 
vided for  the  plant's  earliest  growth.  In  the  almond,  for  instance 
(Fig.  108),  the  large  cotyledons  are  so  thickened  by  this  nourishing 
matter,  deposited  in  their  tissue,  that  they  have  not  the  appearance 
of  leaves.  It  is  the  same  in  the  Plum  and  Cherry  (Fig.  Ill"), 
and  in  the  Apple,  only  on  a  smaller  scale  (Fig.  110,  111)  ;  and  the 
Beech  (Fig.  112  - 114)  and  the  Bean  (Fig.  115-117)  afford  familiar 


FIG.  108.  Embryo  (kernel)  of  the  Almond.  109.  Same,  with  one  cotyledon  removed,  to 
show  the  plumule,  a. 

FIG.  110.  Section  of  an  Apple-seed,  magnified,  cutting  through  the  thickness  of  the 
cotyledons.    111.  Embryo  of  the  same,  extracted  entire,  the  cotyledons  a  little  separated. 

FIG.  llla.  Germination  of  the  Cherry,  showing  the  thick  cotyledons  little  altered,  and 
the  plumule  developing  the  earliest  real  foliage. 


PLANTS    FROM    THE    SEED. 


75 


illustrations  of  the  kind.  The  ample  store  of  nourishment  in  such 
cases  enables  the  germinating  plantlet  to  grow  with  remarkable 
vigor,  and  to  develop  the  strong  plumule 
with  its  leaves  before  the  seed-leaves 
have  expanded,  or  the  root  has  obtained 
much  foothold  in  the  soil.  In  these 
instances  the  cotyledons  are  so  much 
thickened  that, 
although  they 
turn  greenish 
in  the  light, 
they  only  im- 
perfectly as- 
sume the  ap- 
i pearance  and 
perform  the  ( 
functions  of  or- 
dinary leaves ; 
and  the  earli- 
est real  foliage 
consists  of  the 
leaves  of  the 
plumule.  Such 
cotyledons 
serve  chiefly 
as  depositories 
of  nourishment 
for  the  germi- 
117  11S      nating  plant.  114 

124.  Still  more  strongly  marked  cases  of  this  kind  are  presented 
by  the  Pea  (Fig.  118,  119),  the  Chestnut  and  Horsechestnut,  the 
Oak  (Fig.  120,  121),  &c.  Here  the  cotyledons  are  excessively 
thickened,  so  as  to  lose  all  likeness  to  leaves  and  all  power  of  ful- 
filling the  office  of  foliage.  Accordingly  they  remain  unchanged 
within    the    seed-coats,    supplying    abundant    nourishment    to    the 


FIG.  112.  A  Beech-nut,  cut  across.  113.  Beginning  germination  of  the  Beech,  showing 
the  plumule  growing  before  the  cotyledons  have  opened  or  the  root  has  scarcely  formed. 
114.  The  same,  a  little  later,  with  the  second  joint  lengthened. 

FIG.  115.  The  embryo  (the  whole  kernel)  of  the  Bean.  116.  Same  early  in  germination  ; 
the  thick  cotyledons  expanding  and  showing  the  plumule.  117.  Same,  more  advanced  in 
germination  ;  the  plumule  developed  into  a  joint  of  stum  bearing  a  pair  of  leaves. 


76 


DEVELOPMENT    OF    FLOWERING    OR    PH^ENOGAMOL'S 


plumule,  which  gives  rise  to  the  first  leaves  that  appear.  As  the 
radicle  itself  scarcely  if  at  all  elongates,  the  cotyledons  are  not  ele- 
vated in  germination  but  remain  under  ground  (i.  e.  are  hypogceous), 
or  rest  on  the  surface  of  the  soil. 

125.  Jn  all  the  foregoing  illustrations  the 
nourishment  provided  for  the  growth  of  the 
embryo  into  a  plantlet  is   deposited  in  the 
tissue  of  the  embryo  itself,  i.  e.  in  the  seed- 
leaves.     In  other 

cases  it  is  depos- 
ited   around    the 

embryo ;  when  it 

forms      what     is 

commonly   called 

the   Albumen    of 

the    seed.      This 

makes     up     the 

principal  bulk  of/ 

the   seed   in   the 

Buckwheat,     In- 
dian   Corn   (Fig. 

126,    127),     and 

most  other    sorts 

of    grain.       The 

greater  the  quan- 
tity  of   this,   the 

floury  part  of  the 

seed,  the  smaller 

or  less  developed 

is     the     embryo, 

or  the  less  thick 

are  its  cotyledons. 

In  the  Morning- 
Glory,  for  instance  (Fig.  122-125),  where  the  embryo  is  surround- 
ed by  mucilaginous  albumen,  the  cotyledons  appear  in  the  seed  as 
a  pair  of  very  thin  and  well-formed  green  leaves.  These  absorb 
the  nourishment  required  for  the  plantlet's   earliest  growth  from 


FIG.  118.     Embryo  of  a  Pea.    119.  The  same  in  germination. 

FIG.  120.    An  acorn,  divided  lengthwise,  showing  a  section  of  the  very  thick  and  fleshy 
cotyledons  and  the  very  small  radicle.    121.  Germination  of  the  acorn. 


PLANTS    FROM    THE    SEED. 


77 


the  surrounding  albumen,  which  in  germination  is  gradually  lique- 
fied, its  starch  or  amyloid  being  transformed  into  dextrine  and 
sugar  (80,  82,  83).  Thus  nourished,  the  radicle  rapidly  lengthens 
into  a  stem,  and  develops  a  root  from  its  122  123 

lower  extremity,  connecting  it  with  the 


soil ;  and  when  the  enlarging  cotyledons 

extricate  themselves  froni  the  decaying 
seed-coats  and  expand  in 
the  light  as  the  first  pair 
of  leaves,  the  plantlet  is 
already  established  as  a 
complete  miniature  vege- 
table, able  to  nourish  it- 
self, and  make  sufficient 
provision  for  its  own  con- 
tinued growth.  m  125 

126.  The  embryo  in  seeds  provided  with  albumen 
is  sometimes  very  small,  as  in  Fig.  131,  or  even 
much  more  minute,  and  with  its  parts  so  rudimentary 
that  they  are  hardly  or  not  at  all  discernible  previous 
to  their  gradual  development  in  germination.  But 
sometimes  it  is  pretty  large,  and  with*  all  its  parts 
129         obvious    in    the    seed ;    as    in    the    Morning-Glory 

and  in  Indian  Corn  (Fig.  122).     The  latter  has  a  highly  organized 

FIG.  122.  Seed  and  embryo  of  the  common  Morning-Glory,  cut  across  ;  the  latter  seen 
edgewise.  123.  Embryo  of  the  same,  detached  and  straightened,  seen  flatwise.  124.  Germi- 
nating Morning-Glory.     125.    The  same  further  advanced  ;  its  two  thin  seed-leaves  expanded. 

FIG.  126.  A  grain  of  Indian  Corn,  seen  flatwise,  divided  through  the  embryo,  which  is 
viewed  lying  on  the  albumen,  which  makes  the  principal  bulk  of  the  seed. 

FIG.  127.  Another  grain  of  Corn,  cut  through  the  middle  in  the  opposite  direction,  divid- 
ing the  embryo  through  its  thick  cotyledon  and  its  plumule,  the  latter  consisting  of  two 
leaves,  one  enclosing  the  other. 

FIG.  128.  The  embryo  taken  out  whole :  the  thick  mass  is  the  cotyledon  ;  the  narrow 
body  partly  enclosed  by  it  is  the  plumule  ;  the  little  projection  at  its  base  is  the  very  short 
radicle  enclosed  in  the  sheathing  base  of  the  first  leaf  of  the  plumule. 

FIG.  129.    A  grain  of  Indian  Corn  in  germination. 

7* 


78 


DEVELOPMENT    OF   PILENOGAMOUS    PLANTS. 


embryo,  with  a  strong  and  well-developed  plumule,  of  several  leaves 
enwrapped  one  within  another ;  and,  being  amply  nourished  by  the 
copious  mealy  albumen,  it  sprouts  with  re- 
markable vigor,  sending  up  three  or  four 
leaves  in  rapid  succession  before  the  earliest 
has  completed  its  growth,  at  the  same  time 
sending  forth  additional  roots  downwards  into 
the  soil.  Here  also,  as  in  the  Pea  and  the 
Oak,  &c.  (124)  the  germination  is  hypogceous, 
the  cotyledons  remaining  in  the  seed  under 
ground,  and  the  leaves  which 
appear  above  ground  belonging 
to  the  plumule.  This  is  also  the/ 
case  in  the  Iris  (Fig.  132)  and 
most  plants  of  the  same  class. 
But  in  the  Onion  the  co- 
tyledon (which  is  single) 
lengthens,  raises  the  seed 
out  of  the  ground,  and  be- 
comes the  first  leaf. 

127.  In  Indian  Corn  (Fig. 
130),  in  Iris  (Fig.  132),  and 
also  in  the  germinating  Cher- 
ry (Fig.  IIP),  Oak  (Fig. 
121),  and  Pea  (Fig.  119),  the  leaves  of  the  plumule 
succeed  one  another  singly,  that  is,  there  is  only  one 
upon  each  joint  of  stem :  in  other  words,  the  leaves  are 
alternate.  Whereas  in  the  seedling  Beech  and  the  Bean 
(Fig.  114,  11,7)  these  early  leaves  are  in  pairs,  that  is, 
are  opposite.  A  similar  difference  is  to  be  noticed  in  the 
embryo  as  to  the 

128.  Number  Of  Cotyledons.  All  the  earlier  illustra- 
tions are  taken  from  plants  which  have  a  pair  of  cotyle- 
dons, or  seed-leaves,  belonging  to  the  first  joint  of  stem, 
that  is,  to  the  radicle.  Such  embryos  are  accordingly 
said  to  be  Dicotyledonous,  —  a  name  expressive  of  this  fact. 
But  in  the  Lily,  Onion,  Iris,  Indian  Corn,  and  the  like,  the  embryo 


FIG.  130.    Indian  Corn  more  advanced  in  germination,  and  with  a  cluster  of  roots. 
FIG.  131.    Section  of  a  seed  of  Iris  or  Flower-de-Luce,  magnified,  showing  the  small  embryo 
enclosed  in  the  albumen,  near  its  base.     132.  Germinating  plantlet  of  Iris. 


THE    ROOT. 


79 


has  only  one  cotyledon  or  true  seed-leaf  (Fig.  128,  &c.) ;  the  other 
leaves,  if  any  are  apparent,  are  enclosed  by  the  cotyledon  and  be- 
long to  the  plumule ;  and  the  embryo  with  one  cotyledon  is  ac- 
cordingly termed  Monocotyledonous.  The  difference  in  this 
respect  coincides  with  striking  differences  in  the 
structure  of  the  stems,  leaves,  and  blossoms,  and 
lays  a  foundation  for  the  division  of  Flowering  or 
Phtenogamous  plants  (114)  iuto  two  great  Classes. 

129.  In  a  few  plants,  such  as  Pines,  the  embryo 
is  provided  with  from  three  to  ten  cotyledons, 
which  expand  into  a  circle  of  as  many  green  leaves 
in  germination  (Fig.  133,  134)  :  such  an  embryo 
is  said  to  be  Polycotyledoxous,  i.  e.  of  many 
cotyledons. 

130.  Having  taken  this  general  survey  of  the 
development  of  Phamogarnous  plants  from  the 
seed,  and  of  their  common  plan  of  growth,  their 
further  development  and  their  morphology  may 
best  be  studied  by  examining  in  succession  the  three  universal 
organs  of  vegetation  (116)  of  which  they  all  consist,  viz.  the  Eoot, 
Stem,  and  Leaves. 


CHAPTER     III. 

OF   THE   ROOT,   OR   DESCENDING   AXIS. 

131.  The  Root  is  the  descending  axis  (120),  or  that  portion  of 
the  body  of  the  plant  which  grows  downwards,  ordinarily  fixing  the 
vegetable  to  the  soil  and  absorbing  nourishment  from  it.  As  already 
mentioned  (121),  the  root  grows  in  length  by  continual  additions  of 
new  fabric  to  its  lower  extremity,  elongating  from  that  part  only  or 
chiefly ;  so  that  the  tip  of  a  growing  root  always  consists  of  the  most 
newly  formed  and  active  tissue.  It  begins,  in  germination,  at  the 
root-end  of  the  radicle.  That  only  this  extremity  of  the  radicle  is 
root  is  evident  from  the  mode  in  which  the  radicle  grows,  namely, 


FIG.  133.     Section  of  a  seed  of  a  Pine,  with  its  embryo  of  several  cotyledons.     134.  Early 
seedling  Pine,  with  its  stemlet,  displaying  its  six  seed-leaves. 


80 


THE   ROOT, 


by  lengthening  throughout  every  part;  which  is  a  characteristic 
feature  of  the  stem. 

132.  The  root,  however,  does  not  grow  from  its  very  apex,  as  is 
commonly  stated ;  but  the  new  formation  (by  continued  multiplica- 
tion of  cells,  33)  takes  place  just  behind  the 
apex  (Fig.  135),  which  consists  of  an  obtusely 
conical  mass  of  older  cells.  As  these  wear 
away  or  perish,  they  are  replaced  by  the  layer 
beneath ;  and  so  the  advancing  point  of  the 
root  consists,  as  inspection  plainly  shows,  of 
older  and  denser  tissue  than  the  portion  just 
behind  it.  The  point  of  every  branch  of  the 
root  is  capped  in  the  same  way.  It  follows 
that  the  so-called  spongioles  or  spongelets  of 

the  roots,  or  enlarged  tips  of  delicate  forming  tissue,  have  no  ex- 
istence. Not  only  are  there  no  special  organs  of  this  sort,  but 
absorption  evidently  does  not  take  place,  to  any  considerable  extent, 
through  the  rather  firm  tissue  of  the  very  point  itself. 

133.  Absorption  by  Roots.  As  the  surface  of  the  root,  like  every 
part  of  a  plant,  consists  of  closed  cells,  it  is  evident  that  the  moist- 
ure it  so  largely  takes  in  must  iss 

be  imbibed  through  the  walls  of 
the  cells,  by  endosmose  (40) ; 
and  that  the  whole  surface  of  a 
fresh  root  will  take  part  in  ab- 
sorption. The  newer  the  root, 
however,  the  more  actively  does 
it  absorb,  the  cells  then  having 
thinner  walls.  As  they  become 
older,  the  superficial  layer  of 
cells  thicken  their  walls  and 
form  a  kind  of  skin,  or  epider- 
mis (69),  through  which  absorp- 
tion does  not  take  place  so  free-  13r 
ly.  Roots  accordingly  absorb  mostly  by  their  fresh  tips  and  the 
adjacent  parts ;  and  these  are  constantly  renewed  by  growth,  and 


FIG.  135.  The  tip  of  the  root  of  a  seedling  Maple  (Fig.  106),  magnified  :  a,  the  place  where 
growth  is  mainly  taking  place,  hy  cell-multiplication  :  b,  the  original  tip  of  the  radicle. 

FIG.  136, 137.  Tortious  of  the  surface  of  the  same,  highly  magnified,  showing  the  nature 
of  the  root-hairs  or  fibrils. 


ITS    STRUCTURE    AND    GROWTH.  81 

extended  farther  into  the  soil.     The  absorbing  surface  of  the  new 
parts  of  roots  is  greatly  increased  by  the 

134.  Root-hairs,  or  delicate  fibrils  which  they  bear.  These  are 
often  discernible  by  the  naked  eye,  as  in  the  young  seedling  Maple 
(Fig.  106),  and  may  almost  always  be  plainly  shown  by  a  moderate 
magnifying  power,  as  in  Fig.  135 ;  while  a  higher  power  distinctly 
reveals  their  nature,  as  prolongations  of  some  of  the  superficial  cells 
from  a  certain  point  into  slender  tubes  (Fig.  136,  137),  thus  largely 
increasing  the  absorbing  surface.  As  fast  as  the  superficial  cells  are 
converted  into  epidermis,  the  root-hairs  die  away,  fresh  ones  taking 
their  place  on  the  newer  parts. 

135.  The  advancing  extremity  of  the  root  consists  of  parenchyma 
alone ;  but  vessels  and  woody  tissue  appear  in  the  forming  root 
soon  after  their  appearance  in  the  radicle  or  stemlet  above.  The 
arrangement  of  the  woody  matter  is  generally  the  same  as  in  the 
stem,  except  that  the  root  seldom  exhibits  a  distinct  pith.  The  root 
increases  in  diameter  in  the  same  manner  as  the  stem.  (Chap.  IV. 
Sect.  IV.,  V.) 

136.  The  growth  of  the  root  and  its  branches  keeps  pace  with 
the  development  of  the  stem.  As  the  latter  shoots  upward  and 
expands  its  leaves,  from  which  water  is  copiously  exhaled  during 
vigorous  vegetation,  the  former  grow  onward  and  continually  renew 
the  tender  tissue  through  which  the  absorption,  required  to  restore 
what  is  lost  by  evaporation  or  consumed  in  growth,  is  principally 
effected.  Hence  the  danger  of  disturbing  the  active  roots  during 
the  season  of  growth.  In  early  summer,  while  new  branchlets  and 
leaves  are  developing,  and  when  the  sap  is  rapidly  consumed  by  the 
fresh  foliage,  the  rootlets  are  also  in  rapid  action,  are  extending  at  a 
corresponding  rate,  and  their  tender  absorbing  points  are  most  fre- 
quently renewed.  They  cannot  now  be  removed  from  the  soil  with- 
out injury,  at  the  very  time  when  their  action  is  essential  to  restore 
the  liquid  which  is  continually  exhaled  from  the  leaves.  But  at  the 
close  of  summer,  as  the  leaves  become  inactive  and  the  growth  of 
the  season  is  attained,  the  rootlets  also  cease  to  grow,  the  epidermis 
forms  a  comparatively  firm  covering  quite  down  to  the  tip,  and  ab- 
sorption at  length  ceases.  This  indicates  the  proper  period  for 
transplanting,  namely,  in  the  autumn  after  vegetation  is  suspended, 
or  in  early  spring  before  it  recommences. 

137.  This  elongation  of  roots  by  their  advancing  points  alone  is 
admirably  adapted   to   the    conditions    in  which   they  are   placed. 


82  THE   ROOT, 

Growing  as  they  do  in  a  medium  of  such  unequal  resistance  as  the 
soil,  if  roots  increased  like  growing  stems,  by  the  elongation  of 
their  whole  body,  they  would  be  thrown,  whenever  the  elongating 
force  was  insufficient  to  overcome  the  resistance,  into  knotted  or  con- 
torted shapes,  ill  adapted  for  the  free  transmission  of  fluid.  But, 
lengthening  only  at  their  farthest  extremity,  they  insinuate  them- 
selves with  great  facility  into  the  crevices  or  yielding  parts  of  the 
soil,  and  afterwards  by  their  expansion  in  diameter  enlarge  the 
cavity ;  or,  when  arrested  by  insuperable  obstacles,  their  advancing 
points  follow  the  surface  of  the  opposing  body  until  they  reach  a 
softer  medium.  In  this  manner,  too,  they  readily  extend  from  place 
to  place,  as  the  nourishment  in  their  immediate  vicinity  is  consumed. 
Hence,  also,  may  be  derived  a  simple  explanation  of  the  fact,  that 
roots  extend  most  rapidly  and  widely  in  the  direction  of  the  most 
favorable  soil,  without  supposing  any  self-determining  power  beyond 
what  belongs  to  all  growing  parts.     (Chap.  XIII.) 

138.  We  have  taken  the  root  of  the  seedling  as  an  example  and 
epitome  of  that  of  the  whole  herb  or  tree ;  as  we  rightly  may,  for 
in  its  whole  development  the  root  produces  no  other  parts  ;  it  bears 
nothing  but  naked  branches,  which  spring  from  different  portions  of 
the  surface  of  the  main  root,  nearly  as  this  sprung  from  the  radicle, 
and  exactly  imitate  its  growth.  They  and  their  ramifications  are 
mere  repetitions  of  the  original  descending  axis,  serving  to  multiply 
the  amount  of  absorbing  surface.  The  branches  of  the  root,  more- 
over, shoot  forth  irregularly,  or  at  least  in  no  order  like  that  of  the 
branches  of  the  stem,  which  have  a  symmetrical  arrangement,  de- 
pendent upon  the  arrangement  of  the  leaves  (1G6). 

139.  To  the  general  statement  that  roots  give  birth  to  no  other 
organs,  there  is  this  abnormal,  but  by  no  means  unusual  exception, 
that  of  producing  buds,  and  therefore  of  sending  up  leafy  branches. 
Although  not  naturally  furnished  with  buds,  like  the  stem,  yet, 
under  certain  circumstances,  the  roots  of  many  trees  and  shrubs, 
and  of  some  herbs,  have  the  power  of  producing  them  abundantly. 
Thus,  when  the  trunk  of  a  young  Apple-tree  or  Poplar  is  cut  off 
near  the  ground,  Avhile  the  roots  are  vigorous  and  full  of  elaborated 
sap,  those  which  spread  just  beneath  the  surface  produce  buds,  and 
give  rise  to  young  shoots.  The  roots  of  the  Madura,  or  Osage 
Orange,  habitually  give  rise  to  such  irregular  or  adventitious  (1G8) 
buds  and  branches. 

140.  Although  the  root  does  not  produce  ascending  axes,  or  stems, 


IN   ANNUAL    AND    BIENNIAL    PLANTS.  83 

except  in  certain  rather  unusual  instances,  yet  stems  habitually  pro- 
duce roots,  whenever  circumstances  favor  it,  namely,  when  they  are 
covered  by  the  damp  and  moist  soil,  or  rest  on  its  surface.  Roots 
accordingly  may  be  distinguished  into  primary  and  secondary. 

141.  The  Primary  Root  is  that  which  originates  from  the  root  end 
of  the  embryo  in  germination,  including  also  its  branches.  If  this 
continues  as  a  main  root,  it  commonly  forms  a  tap-root.  But  very 
often  the  main  root,  is  soon  lost  in  the  branches.  Sometimes  a 
cluster  of  roots  is  produced  directly  from  the  lower  extremity  of 
the  radicle,  as  in  the  Pumpkin,  and  Indian  Corn  (Fig.  180).  In  the 
latter  the  second  and  the  succeeding  short  joints  of  stem  also  send 
out  roots.     These  are  early  instances  of 

142.  Secondary  Roots,  i.  e.  roots  emitted  by  other  parts  of  the 
ascending  axis  than  the  radicle.  Most  creeping  plants  produce 
them  at  every  joint ;  and  most  branches,  when  bent  to  the  ground 
and  covered  with  earth,  so  as  to  afford  the  moisture  and  darkness 
they  require,  will  strike  root.  So,  often,  will  separate  pieces  of 
young  stems,  if  due  care  be  taken ;  as  when  plants  are  propagated 
by  cuttings.  Cryptogamous  plants,  growing  from  spores  and  hav- 
ing no  embryo  stem  or  axis  to  commence  with,  are  furnished  with 
secondary  roots  only. 

143.  Viewed  as  to  the  duration  of  the  plant,  roots  are  distin- 
guished into  annual,  biennial,  and  perennial. 

144.  Annual  Roots  are  those  of  a  plant  which  springs  from  the 
seed,  flowers,  and  dies  the  same  year  or  season.  Such  plants 
always  have  fibrous  roots,  composed  of  numerous  slender  branches, 
fibres,  or  rootlets,  proceeding  laterally  from  the  main  or  tap-root ; 
or  else  the  whole  root  divides  at  once  into  such  fibrous  branches,  as 
in  all  annual  Grasses  (Fig.  130).  These  multiplied  rootlets  are 
well  adapted  for  absorption  from  the  soil,  but  for  that  alone.  The 
food  which  the  roots  absorb,  after  being  digested  and  elaborated  in 
the  leaves,  is  all  expended  in  the  production  of  new  leafy  branches, 
and  at  length  of  blossoms.  The  flowering  process  and  the  maturing 
of  the  fruit  exhaust  the  vegetable  greatly  (in  a  manner  hereafter  to 
be  explained),  consuming  all  the  nourishing  material  which  it  con- 
tains, or  storing  it  up  in  the  fruit  or  seed  for  its  offspring ;  and  the 
exhausted  plant  perishes  at  the  close  of  the  season,  or  whenever  it 
has  fully  gone  to  seed. 

145.  Biennial  Roots  are  those  of  plants  which  do  not  blossom  until 
the  second  season,  and  which  die  when  they  have  matured  their 


84 


THE   ROOT. 


seed.     Such  plants  send  up  no  lengthened  stem  during  the  first 
summer,  but  produce  a  large  tuft  of  leaves  next  the  ground,  and 

proceed  to  elaborate  what  they  re- 
ceive from  the  roots  and  from  the  air 
into  organic  or  nourishing  matter,  and 
store  it  up  in  the  root,  in  the  form  of 
starch,  vegetable  jelly,  and  the  like. 
The  root  enlarges,  or  becomes  fleshy, 
as  this  accumulates.  In  biennials  this 
accumulation  generally  takes  place  in 
the  primary  or  main  root,  as  in  the 
Radish,  Carrot,  Beet,  &c.  This,  when 
only  moderately  thickened  and  taper- 
ing downwards,  is  a  common  tap-root : 
when  more  enlarged  and  broadest  at 
the  crown,  or  junction  with  the  ex- 
tremely abbreviated  stem,  it  forms  a 
conical  root,  like  that  of  the  common 
Beet  and  Parsnip :  when  broadest  in 
the  middle  and  tapering  to  both  ends,  it  is  spindle-shaped  or  fusi- 
form, as  in  the  Radish  (Fig.  138)  :  when  much  broader  than  long, 
and  abruptly  contracted  below,  like  a  turnip,  it  is  napiform.  Such 
roots,  abounding  in  nourishment,  are  appropriated  by  man  for  food. 
The  plant  itself  uses  this  store  for  the  same  purpose.  When  the 
vegetation  of  these  biennials  is  resumed,  the  following  spring,  the 
new  shoots,  fed  by  this  abundant  stock  of  nourishment  provided  for 
them,  grow  with  great  vigor,  and  produce  flowers,  fruit,  and  seed 
almost  entirely  at  its  expense ;  and  this  stock  being  exhausted  by  the 
time  the  seeds  are  matured,  when  the  cells  of  the  great  root  will  be 
found  to  be  emptied  of  their  contents  and  dead,  the  plant  perishes. 

146.  Perennial  Roots  are  those  of  plants  which  last  year  after  year. 
In  shrubs  and  trees  the  roots  themselves  live  and  grow  indefinitely ; 
but  in  perennial  herbs  the  same  roots  seldom  survive  more  than  a 
year  or  two,  and  a  new  set  is  formed  annually.  Here,  also,  a  store 
of  nourishment  for  the  vigorous  commencement  of  the  succeeding 
year's  growth  is  not  unfrequently  deposited  in  the  root.  The  Sweet 
Potato,  the  Peony,  and  the  Dahlia  (Fig.  139),  furnish  good  illustra- 
tions of  the  kind.  These  roots  are  generally  fa scicled  or  clustered; 
that  is,  they  consist  of  a  cluster  of  roots  from  the  base  of  the  stem. 

FIG.  138.    Fusiform  root  of  the  Radish,  with  some  foliage. 


ITS    STRUCTURE    AND    GROWTH. 


85 


While  some  of  these  remain  slender  and  serve  merely  for  absorption, 

others,  thickened  by  this  deposit,  may  become  tuberous  (as  in  Fig. 

139)  ;  and  buds,  formed  on  the  stem 

just  above,  draw  upon  this  store  when 

they  start  into  growth  in  the  spring. 

These   particular   roots   perish  when 

exhausted   of   their    store ;    but   new 

accumulations    have  meanwhile  been 

formed  in  some  of  the  roots  of  the 

season,  which  serve  the  same  purpose 

the  following  spring  ;  and  so  the  plant 

survives,  year  after  year. 

147.  Some  less  ordinary  modifica- 
tions of  roots  remain  to  be  noticed. 
It  has  already  been  stated  that  they 
may  spring  (as  secondary  roots,  142) 
from  any  part  of  the  stem,  although 
they  commonly  do  so  only  when  this  139 

rests  on  or  is  covered  by  the  soil,  which  affords  the  darkness  and 
moisture  congenial  to  them.  Some  stems,  however,  strike  root  freely 
in  the  open  air,  forming 

148.  Aerial  Roots.  The  Ivy  of  Europe,  our  own  Poison  Ivy  (Rhus 
Toxicodendron),  and  the  Trumpet  Creeper  climb  by  such  roots,  in 
the  form  of  small  rootlets,  which  attach  themselves  to  the  bark  of 
trees,  &c.  These  serve  merely  for  mechanical  support.  Other 
plants  produce  larger  aerial  roots,  which,  emitted  from  the  stem  in 
the  open  air,  descend  to  the  ground  and  establish  themselves  in  the 
soil.  This  may  be  observed,  on  a  small  scale,  in  the  stems  of  In- 
dian Corn,  where  the  lower  joints  often  produce  roots  which  grow 
to  the  length  of  several  inches  before  they  reach  the  ground.  More 
remarkable  cases  of  the  kind  abound  in  those  tropical  regions  where 
the  sultry  air,  saturated  with  moisture  for  a  large  part  of  the  year, 
favors  the  utmost  luxuriance  of  vegetation.  The  Pandanus  or 
Screw-Pine  (a  Palm-like  tree,  often  cultivated  in  our  conserva- 
tories) affords  a  well-known  instance.  Here  (Fig.  140)  strong  roots, 
emitted  in  the  open  air  from  the  lower  part  of  the  trunk,  and  soon 
reaching  the  soil,  give  the  tree  the  appearance  of  having  been  par- 
tially raised  out  of  the  ground.  The  famous  Banyan-tree  of  India 
(Fig.  142)  affords   a  still  more   striking  illustration.     In  this   the 


FIG.  139.     Fascicled  tuberous  roots  of  the  Dahlia. 


86 


THE   ROOT. 


aerial  rootlets  strike  from  the  horizontal  branches  of  the  tree,  often 
at  a  great  height,  at  first  swinging  free  in  the  air,  but  finally  reach- 
in";  and  establishing 
themselves  in  the 
ground,  where  they 
increase  in  diame- 
ter and  form  acces- 
sory trunks,  sur- 
rounding the  origi- 
nal boll  and  sup- 
porting the  wide- 
spread canopy  of 
branches  and  foli- 
age. Very  similar 
is  the  economy  of 
the  Mangrove  (Fig. 
141),  which  forms 
impenetrable  thick- 
ets on  low  and  mud- 
dy sea-shores  in  the 
tropics,  and  even 
occurs  on  the  coast 
of  Florida  and  Lou- 
isiana. Here  aerial  roots  spring  not  only  from  the  main  trunk,  as 
in  the  Pandanus,  but  also  from  the  branchlets,  as  in  the  Banyan. 


FIG.  140.    The  Pandanus,  or  Screw-Pine;  with,  141,  a  Mangrove-tree  (Rhizophora  Mangle} 
FIG.  142.     The  Banyan-tree,  or  Indian  Fig  (Ficus  Indica). 


EPIPHYTES    OR    AIR-PEANTS. 


87 


Moreover,  this  tendency  to  shoot  in  the  air  is  shown  even  in  the 
embryo,  which  begins  to  germinate  while  the  fruit  is  yet  attached  to 
the  parent  branch,  often  elongating  its  radicle  to  the  length  of  a  foot 
or  more  before  the  fruit  falls  to  the  ground. 

149.  Epiphytes,  or  Air-PlailtS,  exhibit  a  further  peculiarity.  Their 
roots  not  only  strike  in  the  open  air,  but  throughout  their  life  have 
no  connection  with  the  soil.  These  generally  grow  upon  the  trunks 
and  branches  of  trees ;  their  roots  merely  adhering  to  the  bark  to 
fix  the  plant  in  its  position,  or  else  hanging  loose  in  the  air,  from 
which  such  plants  draw  all  their  nourishment.  Of  this  kind  are  a 
large  portion  of  the  gorgeous  Orchidaceous  plants  of  very  warm  and 
humid  climes,  which  are  so  much  prized  in  hot-houses,  and  which, 
in  their  flowers  as  well  as  their  general  aspect,  exhibit  such  fantastic 
and  infinitely  varied  forms.     Some  of  the  flowers  resemble  butter- 


flies,  or  strange  insects,  in  shape  as   well  as  in  gaudy  coloring ; 
such,  for  example,  as  the  Oncidium  Papilio  (Fig.  143).     To  another 


FIG.  143.     Oncidium  Papilio,  and,  144,  Comparettia  rosea;  two  epiphytes  of  the  Orchis 
family  ;  showing  the  mode  in  which  these  Air-plants  grow. 


88 


THE    ROOT. 


family  of  Epiphytic  plants  belongs  the  Tillandsia,  or  Long  Moss, 
which,  pendent  in  long  and  gray  tangled  clusters  or  festoons  from 
the  branches  of  the  Live-Oak  or  Long-leaved  Pine,  gives  such  a 
peculiar  and  sombre  aspect  to  the  forests  of  the  warmer  portions 
of  our  Southern  States.  They  are  called  Air-plants,  in  allusion  to 
the  source  of  their  nourishment ;  and  Epiphytes,  from  their  grow- 
ing upon  other  plants,  and  in  contradistinction  to 

150.  Parasites,  that  not  only  grow  upon  other  vegetables,  but  live 
at  their  expense ;  which  Epiphytes  do  not.  Parasitic  plants  may 
be  divided  into  two  sorts,  viz. :  —  1st,  those  that  have  green  foliage  ; 
and  2d,  those  that  are  destitute  of  green  foliage.  They  may  vary 
also  in  the  degree  of  parasitism ;  some  being  absolutely  dependent 
upon  the  foster  plant  for  nourishment,  while  others,  such  as  the 
Cursed  Fig  (Clusia  rosea)  of  Tropical  America,  often  take  root  in 
the  soil,  and  thence  derive  a  part  of  their  support.  The  latter  oc- 
curs only  in 

151.  Green  Parasites,  or  those  furnished  with  green  foliage,  or 
proper  digestive  organs  of  their  own.     These   strike   their  roots 


through  the  bark  and  directly  into  the  new  wood  of  the  foster 
plant;  whence  they  draw  the  ascending,  mostly  crude  sap,  which 

they  have  to  assimilate  in 
their  own  green  leaves. 
The  Mistletoe  is  the  most 
familiar  example  of  this 
class.  It  is  always  com- 
pletely parasitic,  being  at  no 
period  connected  with  the 
earth ;   but  the  seed  germinates  upon  the  trunk  or  branch  of  the 


FIG.  145.    Roots  of  Gerardia  flava  ;  some  of  the  rootlets  attaching  themselves  parasitically 
to  the  root  of  a  Blueberry.     (From  a  drawing  by  Mr.  J.  Stauffer  ) 
FIG.  146.     Section  of  one  of  the  attached  rootlets,  showing  the  union. 


PARASITIC    PLANTS. 


89 


tree  where  it  happens  to  fall,  and  its  nascent  root,  or  rather  the 
woody  mass  that  it  produces  in  place  of  the  root,  penetrates  the 
bark  of  the  foster  stem,  and  forms  as  close  a  junction  with  its  }roung 
wood  as  that  of  a  natural  branch.  The  Cursed  Fig,  commonly  be- 
ginning as  a  parasite,  sends  down  aerial  roots,  some  of  which  strike 
into  the  wood  of  the  foster  tree  lower  down,  while  others  descend 
to  the  ground  and  draw  from  it  a  portion  of  their  sustenance  in  the 
ordinary  manner.  Some  common  herbaceous  plants,  hitherto  not 
suspected  of  such  habits,  have  recently  been  found  to  fix  themselves 
clandestinely,  under  ground,  by  means  of  some  of  their  rootlets,  to 
the  roots  of  neighboring  plants,  and  furtively  draw  from  them  a 
portion  of  their  sustenance.  This  is  the  case  with  our  Comandra, 
as  well  as  with  the  Thesiums  of  the  Old  World,  and  also  with  our 
Gerardias  and  many  other  plants  of  that  family,  which  have  long 
been  known  as  uncultivable,  although  the  cause  of  their  being  so 
has  only  lately  been  detected.  It  would  appear  that  this  partial 
parasitism  is  necessary  to  their  existence.  Gerardia  appears  to  im- 
plant its  rootlets  upon  the  bark  of  the  roots  of  neighboring  shrubs, 
and  therefore  to  steal  elaborated  sap  (Fig.  145,  146). 

152.  Pale  or  Colored  Parasites,  such  as  Beech-Drops,  Pine-Sap, 
&c,  are  those  which  are  destitute  of 
green  herbage,  and  are  usually  of  a 
white,  tawny,  or  reddish  hue  ;  in  fact, 
of  any  color  except  green.  These 
strike  their  roots,  or  sucker-shaped 
discs,  into  the  bark,  mostly  that  of 
the  root,  of  other  plants,  and  thence 
draw  their  food  from  the  sap  already 
elaborated.  They  have  accordingly 
no  occasion  for  digestive  organs  of 
their  own,  i.  e.  for  green  foliage. 
The  Dodder  (Fig.  147)  is  a  common 
plant  of  this  kind  which  is  parasitic 
above  ground.  Its  seeds  germinate 
in  the  earth ;  but  when  the  slender 
twining  stem  reaches  the  surrounding 

FIG.  147.  The  common  Dodder  of  the  Northern  States  (Cuscuta  Grono-rii),  of  the  natural 
size,  parasitic  upon  the  stem  of  an  herb  :  the  uncoiled  portion  at  the  lower  end  shows  the 
mode  of  its  attachment.  148.  The  coiled  embryo  taken  from  the  seed,  moderately  magnified. 
149.  The  same  in  germination  ;  the  lower  end  elongating  into  a  root,  the  upper  into  a  thread- 
like leafless  stem. 

8* 


90 


THE   ROOT. 


herbage,  it  forms  suckers,  which  attach  themselves  firmly  to  the 
surface  of  the  supporting  plant,  penetrate  its  epidermis,  and  feed 
upon  its  juices  ;  while  the  original  root  and  base  of  the  stem  perish, 
and  the  plant  has  no  longer  any  connection  with  the  soil.  Thus 
stealing  its  nourishment  ready  prepared,  it  requires  no  proper  diges- 
tive organs  of  its  own,  and,  consequently,  does  not  produce  leaves. 
This  economy  is  foreshadowed  in  the  embryo  of  the  Dodder,  which 
is  a  naked  thread  spirally  coiled  in  the  seed  (Fig.  148,  149),  and 
presenting  no  vestige  of  cotyledons  or  seed-leaves.  A  species  of  Dod- 
der infests  and  greatly  injures  flax  in  Europe,  and  sometimes  makes 
its  appearance  in  our  own  flax-fields,  having  been  introduced  with 
the  imported  seed.  Such  parasites  do  not  live  upon  all  plants  in- 
discriminately, but  only  upon  those  whose  elaborate  juices  furnish  a 
propitious  nourishment.  Some  of  them  are  restricted,  or  nearly  so, 
to  a  particular  species ;  others  show  little  preference,  or  are  found 
indifferently  upon  several  species  of  different  families.  Their  seeds, 
in  some  cases,  it  is  said,  will  germinate  only  when  in  contact  with 
the  stem  or  root  of  the  species  upon  which  they  are  destined  to  live. 
Having  no  need  of  herbage,  such  plants  may  be  reduced  to  a  stalk 
bearing  a  single  flower  (Fig.  965)  or  a  cluster  of  flowers  (Fig.  9G8), 
or  even  to  a  single  blossom  developed  from  a  bud  directly  parasitic 
on  the  bark  of  the  foster  plant.  Of  this  kind  are  the  several  species 
of  Pilostyles  (parasitic  flowers  on  the  shoots  of  Leguminous  plants) 
in  Tropical  America,  one  species  of  which  was  recently  discovered 
by  Mr.  Thurber  near  the  southern  borders  of  New  Mexico.  Here 
the  flowers  are  small,  only  about  a  quarter  of  an  inch  in  diameter. 
The  most  wonderful  plant  of  this  kind  is  that  vegetable  Titan,  the 
Eafflesia  Arnoldi  of  Sumatra  (Fig.  150),  which  grows  upon  the 
stem  of  a  kind  of  Grape-vine.     It  is  a  parasitic  flower,  measuring 


FIG.  150.    Rafflesia  Arnoldi ;  an  expanded  flower,  and  a  bud,  directly  parasitic  on  the  stem 
of  a  vine  :  reduced  to  the  scale  of  half  an  inch  to  a  foot. 


THE    STEM.  91 

nine  feet  in  circumference,  and  weighing  fifteen  pounds  !     Its  color 
is  light  orange,  mottled  with  yellowish-white. 

153.  Among  Cryptogamous  plants,  numerous  Fungi  are  parasitic 
upon  living,  especially  upon  languishing  vegetables  ;  others  infest 
living  animals ;  the  rest  feed  on  dead  or  decaying  vegetable  or 
animal  matters  :  all  are  destitute  of  chlorophyll  or  anything  like 
green  herbage.  It  is  probable  that  our  Monotropa,  or  Indian  Pipe, 
a  pallid  Phamogamous  plant,  looking  like  a  Fungus,  actually  lives 
like  one,  and  draws  its  nourishment,  at  least  in  great  part,  from  the 
decaying  leaves  among  which  it  grows. 


CHAPTER    IV. 

OF   THE   STEM,   OR   ASCENDING   AXIS. 
Sect.  I.    Its  General  Characteristics  and  Mode  op  Growth. 

154.  The  Stem  is  the  ascending  axis,  or  that  portion  of  the  trunk 
which  in  the  embryo  grows  in  an  opposite  direction  from  the  root, 
seeking  the  light,  and  exposing  itself  as  much  as  possible  to  the  air. 
All  Phamogamous  plants  (114)  possess  stems.  In  those  which  are 
said  to  be  acaulescent,  or  stemless,  it  is  either  very  short,  or  concealed 
beneath  the  ground.  Although  the  stem  always  takes  an  ascending 
direction  at  the  commencement  of  its  growth,  it  does  not  uniformly 
retain  it ;  but  sometimes  trails  along  the  surface  of  the  ground,  or 
burrows  beneath  it,  sending  up  branches,  flower-stalks,  or  leaves 
into  the  air.  The  common  idea,  that  all  the  subterranean  portion 
of  a  plant  belongs  to  the  root,  is  by  no  means  correct. 

155.  The  root  gives  birth  to  no  other  organs,  but  itself  directly 
performs  those  functions  which  pertain  to  the  relations  of  the  vege- 
table with  the  soil ;  —  its  branches  bind  the  plant  to  the  earth ;  its 
newly  formed  extremities  or  rootlets  imbibe  nourishment  from  it. 
But  the  aerial  functions  of  vegetation  are  chiefly  carried  on,  not  so 
much  by  the  stem  itself  as  by  a  distinct  set  of  organs  which  it  bears, 
namely,  the  leaves.     Hence,  the  production  of  leaves  is  one  of  the 


92  THE    STEM, 

characteristics  of  the  stem.     These  are  produced  only  at  certain 
definite  and  symmetrically  arranged  points,  called 

156.  Nodes,  literally  knots,  so  named  because  the  tissues  are  here 
more  or  less  condensed,  interlaced,  or  interrupted,  as  is  conspicuous- 
ly seen  in  the  Bamboo,  in  a  stalk  of  Indian  Com,  or  of  any  other 
Grass.  Here  each  node  forms  a  complete  ring,  because  the  leaf 
arises  from  the  whole  circumference  of  the  stem  at  that  place. 
When  the  base  of  the  leaf  or  leafstalk  occupies  only  a  part  of  the 
circumference,  the  nodes  are  not  so  distinctly  marked,  except  by 
the  leaves  they  bear,  or  by  the  scars  left  by  their  fall  (Fig.  151,  &c.) 
They  are  often  called  joints,  and  sometimes,  indeed,  the  stem  is 
actually  jointed,  or  articulated,  at  these  points  ;  but  commonly  there 
is  no  tendency  to  separate  there.  Each  node  bears  either  a  single 
leaf  (as  in  Fig.  Ill,  121,  &c),  or  two  leaves  placed  on  opposite 
sides  of  the  stem  (as  in  Fig.  107),  or  else  tlu-ee  or  more,  placed  in 
a  ring  (in  botanical  language,  a  whorl  or  verticil)  around  the  stem. 
The  naked  portions  or  spaces  that  intervene  between  the  nodes  are 
termed 

157.  Illteriiodes.  The  undeveloped  stem  is,  in  fact,  made  up  of  a 
certain  number  of  these  leaf-bearing  points,  separated  by  short  in- 
tervals ;  and  its  growth  consists,  primarily,  in  the  successive  elonga- 
tion of  these  internodes  so  as  to  separate  the  nodes  more  or  less,  and 
allow  the  leaves  to  expand. 

158.  This  brings  to  view  the  leading  peculiarity  of  the  stem ; 
namely,  that  it  is  formed  of  a  succession  of  similar  parts,  developed 
one  upon  the  summit  of  another,  each  with  its  own  independent 
growth.  Each  developing  internode,  moreover,  lengthens  through- 
out its  whole  body,  unlike  the  root,  which  elongates  continuously 
from  its  extremity  alone  (121).  To  have  a  good  idea  of  this,  we 
have  only  to  observe  the  gradual  evolution  of  a  germinating  plant, 
where  each  internode  develops  nearly  to  its  full  length,  and  ex- 
pands the  leaf  or  pair  of  leaves  it  bears,  before  the  elongation  of 
the  succeeding  one  commences.  As  already  described  (120,  &c), 
the  radicle,  or  internode  which  pre-exists  in  the  embryo,  elongates, 
and  raises  the  seed-leaves  into  the  air ;  they  expand  and  elaborate 
the  material  for  the  next  joint,  the  leaves  of  which  in  turn  prepare 
the  material  for  the  third,  and  so  on.  The  internode  lengthens 
principally  by  the  elongation  of  its  already  formed  cells,  particularly 
in  its  lower  part,  which  continues  to  grow  after  the  upper  portion 
has  finished. 


ITS    STRUCTURE    AND    GROWTH. 


93 


159.  Buds.  The  apex  of  the  stem,  accordingly,  is  always  crowned 
with  an  undeveloped  portion,  with  rudimentary  parts  similar  to 
those  already  unfolded,  that  is,  with  a  Bud.  The  embryo  itself 
may  be  viewed  as  an  internode  (the  radicle)  bearing  the  fundamental 
bud  (the  plumule)  on  its  apex,  from  which  the  whole  plant  is  de- 
velopod,  just  as  an  ordinary  bud  of  a  tree  or  shrub  develops  to 
form  the  growth  of  the  season.  Except  that,  in  the  latter  case,  the 
different  steps  follow  each  other  more  closely ;  for  the  bud  usually 
has  a  considerable  number  of  parts  ready  formed  in  miniature  before 
it  begins  to  grow,  and  has  a  full  store  of  assimilated  sap  accumulated 
in  the  parent  stem  to  feed  upon.  This  is  no  less  the  case  in  many 
strong  embryos  highly  developed  in  the  seed,  and  supplied  with 
abundant  nourishment,  either  in 
the  cotyledons,  as  in  the  Pea 
(Fig.  119)  and  Oak  (Fig.  120), 
or  in  the  albumen,  as  in  Indian 
Corn  (Fig.  126-130).  The 
strong  buds  which  in  many 
shrubs  and  trees  crown  the 
apex  of  a  stem  when  it  has 
completed  its  growth  for  the 
season,  often  exhibit  the  whole 
plan  and  amount  of  the  next 
year's  growth ;  the  nodes,  and 
even  the  leaves  they  bear,  being 
already  formed,  and  only  re- 
quiring the  elongation  of  the 
internodes  for  their  full  ex- 
pansion. This  is  rudely  shown 
in  the  annexed  diagrams,  Fig. 
151,  152.  As  the  bud  (Fig. 
153)  is  well  supplied  with 
nourishment  in  spring  by  the 
stem  on  which  it  rests,  its  axis  elongates  rapidly ;  and  although  the 
growth  commences  with  the  lowest  internode,  yet  the  second,  third, 


FIG.  151.    Diagram  of  the  vertical  section  of  a  strong  bud,  such  as  that  of  Ilorsechestnut. 

FIG.  152.  The  axis  of  the  same  developing,  the  elongation  beginning  with  the  lowest  inter- 
node, soon  followed  by  the  others  in  succession. 

FIG.  153.  A  year's  growth  of  Ilorsechestnut,  crowned  with  a  terminal  bud  :  a,  scars  left 
by  the  bud-scales  of  the  previous  year  :  b,  scars  left  by  the  fallen  leafstalks  :  c,  axillary  buds. 

FIG.  154.    Branch  and  buds  (all  axillary)  of  the  lilac. 


94 


THE    STEM, 


and  fourth  internodes,  &c.  have  begun  to  lengthen  long  before  the 
first  has  attained  its  full  growth.  The  stem  thus  continued  from 
a  terminal  bud  is,  if  it  survive,  again  terminated  with  a  similar  bud 

at  the  close  of  the  season,  which  in  its 
development  repeats  the  same  process. 
A  set  of  narrow  rings  on  the  bark 
(Fig.  153,  a)  commonly  mark  the  limit 
of  each  year's  growth.  These  are  the 
scars  left  by  the  fall  of  the  scales  of 
the  bud ;  and  these,  in  the  Horsechest- 
nut,  and  other  trees  with  large  scaly 
buds,  may  be  traced  back  on  the  stem 
for  a  series  of  years,  growing  fainter 
with  age,  until  they  are  at  length  ob- 
literated by  the  action  of  the  weather 
and  the  distention  caused  by  the  in- 
crease of  the  stem  in  diameter.  The 
same  is  the  case  with  the  more  con- 
spicuous leaf-scars,  or  marks  on  the 
bark  left  by  the  separation  of  the  leaf- 
stalk, which  are  for  a  long  time  con- 
spicuous on  the  shoots  of  the  Horse- 
chestnut  (Fig.  153,  b)  and  the  Mag- 
nolia (Fig.  155). 

160.  A  bud,  therefore,  is  nothing 
more  than  the  first  stage  in  the  de- 
velopment of  a  stem,  with  the  axis  still 
so  short  that  the  rudimentary  leaves 
within  successively  cover  each  other, 
while  the  whole  is  covered  and  pro- 
tected by  the  scales  without.  Buds 
vary  greatly,  however,  in  size,  ap- 
pearance, and  degree  of  development. 
Those  of  many  shrubs  and  trees  are 
minute,  and  hidden  by  the  bark  until 
their  vernal  growth  commences,  as  in 

FIG.  155.  Branch  of  Magnolia  Umbrella,  of  the  natural  size,  crowned  with  the  terminal 
bud  ;  and  below  exhibiting  the  large,  rounded  leaf-scars,  as  well  as  the  rings  or  annular  scars 
left  by  the  fall  of  the  bud-scales  of  the  previous  season.  156.  A  detached  scale  from  a  similar 
bud  ;  its  thickened  axis  is  the  base  of  a  leafstalk  ;  the  membranous  sides  consist  of  the  pair  of 
stipules. 


ITS    STRUCTURE    AND    GROWTH.  95 

Sumac,  Locust,  Honey-Locust  (Fig.  164),  &c. :  in  these  buds  the 
parts  are  few  and  very  rudimentary,  and  are  mostly  formed 
as  they  develop.  In  some,  they  are  naked,  that  is,  are  entirely 
destitute  of  protecting  scales,  and  exhibit  the  forming  leaves  directly 
exposed  to  the  air,  just  as  they  are  hi  herbs.  This  occurs  in  many 
tropical  trees,  but  not  in  all,  and  in  some  shrubs  of  cold  climates, 
such  as  our  Viburnum  nudum  and  V.  lantanoides.  But  the  greater 
number  of  plants  which  have  a  winter  to  endure  are  provided  with 
scaly  buds.  Those  of  Beech  and  Hickory,  as  well  as  of  Horsechest- 
nut  and  Magnolia  already  referred  to,  are  conspicuous  and  well- 
developed  examples.  The  scales  serve  to  protect  the  tender  parts 
within  against  injury  from  moisture  and  from  sudden  changes  in 
temperature  during  the  dormant  state.  To  ward  off  moisture  more 
effectually,  they  are  sometimes  coated  with  a  waxy,  resinous,  or 
balsamic  exudation,  as  is  conspicuous  on  the  scales  of  the  Horse- 
chestnut,  Balsam-Poplar  or  Balm  of  Gilead,  and  Balsam-Fir.  To 
guard  against  sudden  changes  of  temperature,  they  are  often  lined, 
or  the  rudimentary  leaves  within  invested  with  non-conducting 
down  or  wool. 

161.  The  bud-scales  themselves  are  leaves  in  a  modified  state. 
This  is  evident  from  their  situation  and  arrangement,  which  are 
the  same  as  of  the  proper  leaves  of  the  species,  and  by  the  gradual 
transitions  from  the  former  to  the  latter  in  many  plants.  In  the 
tiirions,  or  subterranean  budding  shoots  of  numerous  perennial 
herbs,  and  in  the  unfolding  buds  of  the  Lilac  and  Sweet  Buckeye 
(iEsculus  parviflora),  every  gradation  may  be  traced  between  bud- 
scales  and  foliage,  showing  that  no  absolute  line  can  be  drawn  be- 
tween them,  but  that  the  two  are  essentially  of  the  same  nature,  i.  e. 
are  different  modifications  of  the  same  organ. 

1 62.  Plan  of  Vegetation.  In  fact,  a  simple  stem  bears  nothing  but 
leaves  in  some  form  or  other,  and  its  branches  are  only  repetitions 
of  itself,  following  the  same  laws.  The  embryo  consists  of  a  pri- 
mary joint  of  stem  crowned  with  a  bud,  the  first  leaves  or  leaf  of 
which  takes  the  special  form  of  cotyledons ;  the  following  ones  de- 
velop as  ordinary  foliage,  and  leaf  after  leaf,  or  pair  after  pair,  is 
formed  and  elevated  upon  the  successive  internodes  as  the  stem  is 
built  up.  At  the  close  of  the  growing  season,  if  the  stem  is  to 
endure,  this  is  terminated,  as  it  began,  by  a  bud ;  and  the  bud-scales, 
if  any,  are  leaves  developed  in  this  peculiar  form,  subservient  to 
protection  alone,  and  borne  upon  nodes  which  are  never  separated 


96 


THE    STEM. 


by  elongation  of  the  internodes.  With  the  ensuing  spring  growth 
recommences,  and  another  set  of  internodes,  and  of  nodes  bearing 
ordinary  leaves,  form  the  second  year's  growth,  like  the  first ;  and 
so,  by  annual  increments,  a  simple  leafy  stem  is  developed  and 
carried  up.  Not  only  is  the  whole  stem  growing  from  3-ear  to  year 
thus  composed  of  a  succession  of  similar  growths,  each  the  offspring 
of  the  preceding  and  the  parent  of  the  next, 
but  also  each  annual  growth  itself  consists  of  a 
lineal  succession  of  similar  parts,  viz.  of  leaf- 
bearing  joints  of  stem,  developed  each  upon  its 
predecessor,  and  in  turn  surmounted  by  the 
next  in  the  series.  These  similar  parts,  which 
by  their  repetition  make  up  the  Phamogamous 
plant,  have  been  termed 

163.  PhytOllS  (from  the  Greek  $vt6v,  plant), 
or  plant-elements.  The  first  phyton  is  the 
radicle  of  the  embryo,  with  its  cotyledon  or 
pair  of  cotyledons,  from  its  base  developing  the 
root,  from  above  expanding  its  leaf  or  pair  of 
leaves  (as  already  described  in  detail,  119  — 
122),  and  then  giving  birth  to  the  next  phyton, 
or  joint  of  stem  and  leaf,  and  so  on,  in  lineal 
succession.  So  that  the  whole  herb,  shrub,  or 
tree,  as  to  its  upward  growth,  is  a  multiplica- 
tion of  the  simple  plantlet  it  began  with  as  it 
developed  from  the  seed.  Moreover,  any  joint 
of  stem,  when  favorably  situated  for  the  pur- 
pose, may  produce  secondary  roots  (142),  and 
thus  complete  the  vegetable  individuality,  hav- 
ing all  the  organs  of  vegetation  (116). 

164.  The  repetition  of  these  similar  parts  in 
137  the  direct  line,  each  from  the  summit  of  its  pre- 
decessor, builds  up  a  simple  or  main  stem,  to  which  many  plants  are 
restricted  during  the  first  year's  growth,  and  some,  such  as  Palms 
and  Reeds,  throughout  their  whole  existence.  Their  production 
from  new  starting-points  gives  rise  to  branches. 

FIG.  157.    Diagram  of  a  simple-stemmed  plant,  like  a  Grass,  and  of  the  similar  parts,  or 
phytons,  a  to  g,  of  which  it  is  composed. 


RAMIFICATION.  97 


Sect.  II.     Ramification. 

165.  Branches  spring  from  lateral  or  axillary  buds.  These  are 
new  growing  points,  which  habitually  appear,  or  at  least  may  ap- 
pear, one  (or  occasionally  two  or  three)  in  the  axil  of  each  leaf,  — 
that  is,  in  the  upper  angle  which  the  leaf  forms  with  the  stem.  (See 
Fig.  153,  c,  where  the  point  at  which  the  fallen  leaves  were  attached 
is  marked  by  the  broad  scar,  b,  just  below  the  bud.)  When  these 
buds  grow,  they  give  rise  to  Branches  ;  which  are  repetitions,  as  it 
were,  of  the  main  stem,  growing  just  as  that  did  from  the  seed ;  ex- 
cepting merely,  that,  while  that  was  implanted  in  the  ground,  these 
proceed  from  the  parent  stem.  The  branches  are  in  turn  provided 
with  similar  buds  in  the  axils  of  their  leaves,  capable  of  developing 
into  branches  of  a  third  order,  and  so  on  indefinitely,  producing  the 
whole  ramification  of  the  plant.  The  ultimate  ramifications  are 
termed  Branchlets. 

166.  The  arrangement  of  axillary  buds  depends  upon  that  of  the 
leaves.  When  the  leaves  are  opposite  (that  is,  two  on  each  node, 
placed  on  opposite  sides  of  the  stem),  the  buds  in  their  axils  are 
consequently  opposite  ;  as  in  the  Maple,  Horsechestnut  (Fig.  153), 
Lilac  (Fig.  154),  &c.  When  the  leaves  are  alternate,  or  one  upon 
each  node,  as  in  the  Apple,  Poplar,  Oak,  Magnolia  (Fig.  155),  &c., 
the  buds  implicitly  follow  the  same  arrangement.  Branches,  there- 
fore, being  developed  axillary  buds,  their  arrangement  follows  that 
of  the  leaves.  When  the  leaves  are  alternate,  the  branches  will  be 
alternate ;  when  the  leaves  are  opposite,  and  the  buds  develop  regu- 
larly, the  branches  will  be  opposite.  But  the  perfect  symmetry  of 
the  ramification,  thus  provided  for,  is  frequently  obscured  by  the 

167.  Non-development  of  some  of  the  Buds.    As  the  original  bud  of 

the  embryo  remains  for  a  time  latent  in  the  seed,  growing  only 
when  a  conjunction  of  favorable  circumstances  calls  its  life  into 
action,  so  also  many  of  the  buds  of  a  shrub  or  tree  may  remain 
latent  for  a  long  time,  and  many  of  them  fail  to  grow  at  all.  In  our 
trees,  most  of  the  lateral  buds  generally  remain  dormant  for  the  first 
season :  they  appear  in  the  axils  of  the  leaves  early  in  summer,  but 
do  not  grow  into  branches  until  the  following  spring ;  and  even  then 
only  a  part  of  them  usually  grow.  Sometimes  the  failure  occurs 
without  appreciable  order;  but  it  often  follows  a  nearly  uniform 
rule  in  each  species.  Thus,  when  the  leaves  are  opposite,  there  are 
9 


98  THE    STEM. 

usually  three  buds  at  the  apex  of  a  branch ;  namely,  the  terminal, 
and  one  in  the  axil  of  each  leaf;  but  it  seldom  happens  that  all 
three  develop  at  the  same  time.  Sometimes  the  terminal  bud  con- 
tinues the  branch,  the  two  lateral  generally  remaining  latent,  as  in 
the  Horsechestnut  (Fig.  153)  ;  sometimes  the  terminal  one  regu- 
larly fails,  and  the  lateral  ones  grow,  when  the  stem  annually  be- 
comes two-forked,  as  in  the  Lilac  (Fig.  154).  The  undeveloped 
buds  do  not  necessarily  perish,  but  are  ready  to  be  called  into  action 
in  case  the  others  are  checked.  When  the  terminal  buds  are 
destroyed,  some  of  the  lateral,  that  would  else  remain  dormant, 
develop  in  their  stead,  incited  by  the  abundance  of  nourishment, 
which  the  former  would  have  monopolized.  In  this  manner  our 
trees  are  soon  reclothed  with  verdure,  after  their  tender  foliage  and 
branches  have  been  killed  by  a  late  vernal  frost,  or  other  injury. 
And  buds  which  have  remained  latent  for  several  years  occasionally 
shoot  forth  into  branches  from  the  sides  of  old  stems.  Such  branch- 
es, however,  more  commonly  originate  from  irregular,  accidental,  or, 
as  they  are  named 

168.  Adventitious  Buds.  It  has  been  already  remarked,  that  roots, 
although  naturally  destitute  of  buds,  do  yet  produce  them  in  certain 
plants,  especially  when  wounded  (139).  So  likewise  do  the  stems 
of  some  shrubs  and  trees,  especially  when  surcharged  with  sap,  as 
is  commonly  seen  in  Willows  and  Lombardy  Poplars.  Here  buds 
break  out  habitually  on  the  sides  of  trunks,  at  least  when  they  are 
wounded  or  pollarded,  or  spring  from  the  cut  surface  where  the  bark 
and  wood  join.  These  adventitious  buds  do  not  originate  from 
nodes,  nor  affect  any  order  in  their  appearance,  but  are  wholly 
casual  as  to  the  point  of  origin.  Thus  the  predestined  symmetry  of 
the  branches  is  obscured  or  interfered  with  in  two  distinct  ways ; 
first,  by  the  failure  of  a  part  of  the  regular  buds  to  develop ;  and 
secondly,  by  the  irregular  and  casual  development  of  buds  from 
other  parts  than  the  axils  of  the  leaves :  to  which  we  may  add,  that 
great  numbers  of  branches  perish  and  fall  away  after  they  have  be- 
gun to  grow.  There  is  still  another  source  of  irregularity,  namely, 
the  production  of 

1G9.  Accessory  Buds.  These  are,  as  it  were,  multiplications  of  the 
regular  axillary  bud,  giving  rise  to  two,  three,  or  more  buds,  instead 
of  one ;  in  some  cases  situated  one  above  another,  in  others  side  by 
side.  In  the  latter  case,  which  occurs  occasionally  in  the  Hawthorn, 
in  certain  Willows,  in  the  Maples  (Fig.  158),  &c,  the  axillary  bud 


RAMIFICATION. 


99 


seems  to  divide  into  three,  or  itself  give  rise  to  a  lateral  bud  on 
each  side.  On  some  shoots  of  the  Tartarean  Honeysuckle  (Fig. 
160)  from  three  to  six  buds  appear  in 
each  axil,  one  above  another,  the  lower 
being  successively  the  stronger  and  earlier 
produced,  and  the  one  immediately  in  the 
axil,  therefore,  grows  in  preference :  oc- 
casionally two  or  more  of  them  grow,  and 
superposed  accessory  branches  result.  It 
is  much  the  same  in  Aristolochia  Sipho, 
except  that  the  uppermost  bud  is  there 
strongest.  So  it  is  in  the  Butternut  (Fig. 
159),  where  the  true  axillary  bud  is  mi- 
nute and  usually  remains  latent,  while  the 
accessory  ones  are  considerably  remote, 
and  the  uppermost,  which  is  much  the 
strongest,  is  far  out  of  the  axil ;  this 
usually  develops,  and  gives  rise  to  an 
extra-axillary  branch. 

170.  Excurrent  and  Deliquescent  Stems. 

Sometimes  the  primary  axis  is  prolonged 
without  interruption,  by  the  continued 
evolution  of  a  terminal  bud,  even  through 
the  whole  life  of  a  tree  (unless  acciden- 
tally destroyed),  forming  an  undivided  158  159 
main  trunk,  from  which  lateral  branches  proceed ;  as  in  most  Fir- 
trees.     Such  a  trunk  is  said  to  be  excurrent.     In  other  cases  the 

main  stem  is  arrested,  sooner  or 
later,  either  by  flowering,  by  the 
failure  of  the  terminal  bud,  or  by 
the  more  vigorous  development 
of  some  of  the  lateral  buds  ;  and 
thus  the  trunk  is  dissolved  into 
branches,  or  is  deliquescent,  as  in 
160  the  White  Elm  and  in  most  of 

our  deciduous-leaved  trees.     The  first  naturally  gives  rise  to  conical 

FIG.  158.    Branch  of  Red  Maple,  -with  triple  axillary  buds,  placed  side  by  side. 

FIG.  159.  Piece  of  a  branch  of  the  Butternut,  with  accessory  buds  placed  one  above 
another  :  a,  the  leaf-scar  :  6,  proper  axillary  bud :  c,  d,  accessory  buds. 

FIG.  160.  Part  of  a  branch  of  Tartarean  Honeysuckle,  with  crowded  accessory  buds  in 
each  axil. 


100  THE    STEM. 

or  spire-shaped  trees ;  the  second,  to  rounded  or  spreading  forms. 
As  stems  extend  upward  and  evolve  new  branches,  those  near  the 
base,  being  overshadowed,  are  apt  to  perish,  and  thus  the  trunk  be- 
comes naked  below.  This  is  well  seen  in  the  excurrent  trunks  of 
Fii's  and  Pines,  which,  when  grown  in  forest,  seem  to  have  been 
branchless  for  a  great  height.  But  the  knots  in  the  centre  of  the 
trunk  are  the  bases  of  branches,  which  have  long  since  perished, 
and  have  been  covered  with  a  great  number  of  annual  layers  of 
wood,  forming  the  clear  stuff  of  the  trunk. 

171.  Definite  and  Indefinite  Annual  Growth  of  Branches.     In  the 

larger  number  of  our  trees  and  shrubs,  especially  those  with  scaly 
buds,  the  whole  year's  growth  is  either  already  laid  clown  rudi- 
mentally  in  the  bud  (159),  or  else  is  early  formed,  and  the  develop- 
ment is  completed  long  before  the  end  of  summer ;  when  the  shoot  is 
crowned  with  a  vigorous  terminal  bud,  as  in  the  Horsechestnut  (Fig. 
153)  and  Magnolia  (Fig.  155),  or  with  the  uppermost  axillary  buds, 
as  in  the  Lilac  (Fig.  154)  and  Elm.  Such  definite  shoots  do  not 
die  down  at  all  the  following  winter,  but  grow  on  directly,  the  next 
spring,  from  these  terminal  or  upper  buds,  which  are  generally  more 
vigorous  than  those  lower  down.  In  other  cases,  on  the  contrary, 
the  branches  grow  onward  indefinitely  through  the  whole  summer, 
or  until  arrested  by  the  cold  of  autumn  :  they  mature  no  buds  at  or 
near  their  summit ;  or  at  least  the  lower  and  older  axillary  buds 
are  more  vigorous,  and  alone  develop  into  branches  the  next  spring ; 
the  later-formed  upper  portion  most  commonly  perishing  from  the 
apex  downward  for  a  certain  length  in  the  winter.  The  Rose  and 
Raspberry,  and  among  trees  the  Sumac  and  Honey  Locust,  are 
good  illustrations  of  this  sort ;  and  so  are  most  perennial  herbs, 
their  stems  dying  down  to  or  beneath  the  surface  of  the  ground, 
where  the  persistent  base  is  charged  with  vigorous  buds,  well  pro- 
tected by  the  ground,  for  the  next  year's  vegetation. 

172.  Propagation  from  Bllds.  Buds,  being,  as  it  were,  new  indi- 
viduals springing  from  the  original  stem,  may  be  removed  and 
attached  to  other  parts  of  the  parent  trunk,  or  to  that  of  another 
individual  of  the  same,  or  even  of  a  different,  but  nearly  related 
species,  where  they  will  grow  equally  well.  This  is  directly  accom- 
plished in  the  operation  of  budding.  In  ingrafting,  the  bud  is 
transferred,  along  Avith  a  portion  of  the  shoot  on  which  it  grew. 
Moreover,  as  the  cut  end  of  such  shoots,  when  buried  in  moist  and 
warm  soil,  will  commonly,  under  due  care,  send  out  adventitious 


KINDS    OF    STEM   AND    BRANCHES.  101 

roots,  they  may  be  made  to  grow  independently,  drawing  their 
nourishment  immediately  from  the  soil,  instead  of  indirectly  through 
the  parent  trunk.  This  is  done  in  the  propagation  of  plants  by 
cuttings.  The  great  importance  of  these  horticultural  operations 
depends  chiefly  on  the  well-known  fact,  that  buds  propagate  indi- 
vidual peculiarities,  which  are  commonly  lost  in  raising  plants  from 
the  seed. 


Sect.  III.     The  Kinds  of  Stem  and  Branches. 

173.  On  the  size  and  duration  of  the  stem  the  oldest  and  most 
obvious  division  of  plants  is  founded,  namely,  into  Herbs,  Shrubs, 
and  Trees. 

174.  Herbs  are  plants  in  which  the  stem  does  not  become  woody 
and  persistent,  but  dies  annually  or  after  flowering,  down  to  the 
ground  at  least.  The  difference  between  annual,  biennial,  and 
perennial  herbs  has  already  been  pointed  out  (144-146).  The 
same  species  is  so  often  either  annual  or  biennial,  according  to  cir- 
cumstances or  the  mode  of  management,  that  it  is  convenient  to 
have  a  common  name  for  plants  that  flower  and  fruit  but  once,  at 
whatever  period,  and  then  perish:  such  De  Candolle  accordingly 
designated  as  Monocarpic  plants ;  while  to  perennials,  whether 
herbaceous  or  woody,  large  or  small,  he  applied  the  counterpart 
name  of  Polycarpic  plants,  signifying  that  they  bear  fruit  an 
indefinite  number  of  times. 

175.  Ulldershrubs,  or  suffruticose  plants,  are  woody  plants  of  hum- 
ble stature,  their  stems  rising  little  above  the  surface.  If  less 
decidedly  woody,  they  are  termed  suffrutescent. 

176.  Shrubs  are  woody  plants,  with  stems  branched  from  or  near 
the  ground,  and  less  than  five  times  the  height  of  a  man.  Between 
shrubs  and  trees  there  is  every  intermediate  gradation.  A  shrub 
which  approaches  a  tree  in  size,  or  imitates  it  in  aspect,  is  said  to 
be  arborescent. 

177.  Trees  are  woody  plants  with  single  trunks,  which  attain  at 
least  five  times  the  human  stature. 

178.  A  Culm  is  a  name  applied  to  the  peculiar  jointed  stem  of 
Grasses  and  Sedges,  whether  herbaceous,  as  in  most  Grasses,  or 
woody  or  arborescent,  as  in  the  Bamboo. 

179.  A  Caudei  is  a  name  usually  applied  to  a  Palm-stem  (Fig. 

9* 


102  THE    STEM. 

184),  to  that  of  a  Tree  Fern  (Fig.  100),  and  to  any  persistent, 
erect  or  ascending,  root-like  forms  of  main  stems. 

180.  Those  stems  which  are  too  weak  to  stand  upright,  but  re- 
cline on  the  ground,  rising,  however,  towards  the  extremity,  are 
said  to  be  decumbent:  if  they  rise  obliquely  from  near  the  base, 
they  are  said  to  be  ascending.  When  they  trail  flat  on  the  ground, 
they  are  procumbent,  prostrate,  or  running  ;  and  when  such  stems 
strike  root  from  their  lower  surface,  as  they  are  apt  to  do,  they  are 
said  to  be  creeping,  or  repent.  They  are  climbing  when  they  cling 
to  neighboring  objects  for  support;  whether  by  tendrils,  as  the 
Vine  and  Passion-flower,  by  their  leafstalks,  as  the  Virgin's  Bower 
(Clematis),  or  by  aerial  rootlets,  as  the  Poison  Oak  (Rhus)  ;  and 
twining,  or  voluble  plants,  when  they  rise,  like  the  Convolvulus,  by 
coiling  spirally  around  stems  or  other  bodies  within  their  reach. 
Other  modifications  of  the  stem  or  branches  have  received  particu- 
lar names,  some  of  which  mei'it  notice  from  having  undoubtedly  sug- 
gested several  operations  by  which  the  cultivator  multiplies  plants. 

181.  A  Stolon  is  a  branch  which  naturally  curves  or  falls  down  to 
the  ground,  where,  favored  by  shade  and  moisture,  it  strikes  root, 
and  then  forms  an  ascending  stem,  capable  of  drawing  its  nourish- 
ment directly  from  the  soil,  and,  by  the  perishing  of  the  portion 
which  connects  it  with  the  parent  stem,  at  length  acquiring  an 
entirely  separate  existence.  The  Currant,  Gooseberry,  &c,  multi- 
ply in  this  way,  and  doubtless  suggested  to  the  gardener  the  opera- 
tion of  layering ;  in  which  he  not  only  takes  advantage  of  and 
accelerates  the  attempts  of  nature,  but  incites  it  in  species  which  do 
not  ordinarily  multiply  in  this  manner. 

182.  A  Sucker  is  a  branch  of  subterranean  origin,  which,  after  run- 
ning horizontally  and  emitting  roots  in  its  course,  at  length,  follow- 
ing its  natural  tendency,  rises  out  of  the  ground  and  forms  an  erect 
stem.  The  Eose,  the  Raspberry,  and  the  Mint  afford  familiar  illus- 
trations, as  well  as  many  other  species  which  shoot  up  stems  "  from 
the  root,"  as  is  generally  thought,  but  really  from  subterranean 
branches.  Cutting  off  the  connection  with  the  original  root,  the 
gardener  propagates  such  plants  by  division. 

183.  A  Runner,  of  which  the  Strawberry  furnishes  the  most  familiar 
example,  is  a  prostrate,  slender  branch,  sent  off  from  the  base  of  the 
parent  stem,  which  strikes  root  at  its  apex,  and  produces  a  tuft  of 
leaves ;  thus  giving  rise  to  an  independent  plant  capable  of  extend- 
ing itself  in  the  same  manner. 


RUNNERS,    TENDRILS,    ETC. 


103 


184.  An  Offset  is  a  similar,  but  short,  prostrate  branch,  with  a  tuft 
of  leaves  at  the  end,  which,  resting  on  the  ground,  there  takes  root, 
and  at  length  becomes   independ- 
ent ;  as  in  the  Houseleek. 

185.  A  Tendril  is  commonly  a 
thread-like,  leafless  branch,  capable 
of  coiling  spirally,  by  which  some 
climbing  plants  attach  themselves 
to  surrounding  bodies  for  support; 
as  in  the  Grape-vine  (Fig.  161). 
But  sometimes  tendrils  belong  to 
the  leaves,  as  in  the  Pea;  when 
they  are  slender  prolongations  of 
the  leafstalk.  Some  tendrils  cling 
by  hooking  their  tips  around  the 
supporting  object.  Others,  such  as 
those  of  the  Virginia  Creeper  (Fig. 
162,  163),  commonly  expand  the 
tips  of  the  tendrils  into  a  flat  disc,  — 
much  as  do  many  aerial  rootlets  (as 
those  of  Ivy)  when  subservient  to 
the  same  office,  —  which  firmly  ad-  1S1 

heres  to  walls  or  the  bark  of  trees,  thus  enabling  the  plant  to  ascend 
and  cover  their  surface.     As  soon  as  they  are  attached,  the  tendril 


FIG.  161.     End  of  a  shoot  of  the  Grape-vine,  with  young  tendrils. 

FIG.  162.     A  portion  of  a  stem  of  Ampelopsis,  or  Virginia  Creeper,  with  a  leaf  and  a  tendril. 

FIG.  163.    Ends  of  the  latter,  enlarged,  showing  the  expanded  tips  by  which  they  cling. 


104 


THE    STEM. 


usually  shortens   itself  by  coiling   spirally,  thus    drawing   up   the 
climbing  shoot  closer  to  the  supporting  object. 

186.  A  Spine  Or  Thorn  is  an  imperfectly  developed,  indurated,  leaf- 
less branch  of  a  woody  plant,  attenuated  to  a  point.     The  nature  of 

spines  is  manifest  in  the  Haw- 
thorn (Fig.  165),  not  only  by 
their  position  in  the  axil  of  a 
leaf,  but  often  by  producing  im- 
perfect leaves  and  buds.  And 
in  the  Sloe,  Pear,  &c,  many 
of  the  stinted  branches  become 
spinose  or  spinescent  at  the 
apex,  tapering  off  gradually  in- 
to a  rigid,  leafless  point,  thus 
exhibiting  every  gradation  be- 
tween a  spine  and  an  ordinary 
branch.  These  spinose  branch- 
es are  less  liable  to  appear  on 
the  cultivated  tree,  when  duly 
cared  for,  such  branches  being 
thrown  mostly  into  more  vigor- 
ous growth.  In  the  Hawthorn, 
the  spines  spring  from  the  mam 
axillary  bud,  while  accessory 
buds  (169),  one  on  each  side,  ap- 
pear, and  one  or  both  grow  the 
165  next  season  into  an  ordinary 
branch.  In  the  Honey  Locust,  it  is  the  uppermost  of  several  ac- 
cessory buds,  placed  far  above  the  axil,  that  develops  into  the  thorn 
(Fig.  164).  And  here  the  spine  itself  branches,  and  sometimes  be- 
comes extremely  compound.  Sometimes  the  stipules  of  the  leaves 
develop  into  spines,  as  in  the  Prickly  Ash.  Sometimes  the  leaf  it- 
self is  developed  as  a  spine  ;  of  which  the  Barberry  affords  a  familiar 
example.  When  the  spine  is  situated  in  the  axil  of  a  leaf  or  a  leaf- 
scar,  it  is  necessarily  of  the  nature  of  a  branch.     When  it  bears  a 


FIG.  164.  Branching  thorn  of  the  Honey  Locust  (Gleditschia),  an  indurated  branch  devel- 
oped from  an  accessory  bud  produced  above  the  axil,  a,  Three  buds  under  the  base  of  the 
leafstalk,  brought  to  view  in  a  section  of  the  stem  and  leafstalk  below. 

FIG.  165.  Thorn  of  the  Cockspur  Thorn,  developed  from  the  central  of  three  axillary  buds ; 
one  of  the  lateral  buds  is  seen  at  its  base. 


ITS    SUBTERRANEAN   MODIFICATIONS. 


105 


bud  oi-  branch  in  its  axil  (as  in  the  Barberry,  Fig.  296),  it  must  be 
of  the  nature  of  a  leaf. 

187.  The  Subterranean  Modifications  of  the  Stem  are  scarcely  less 

numerous  and  diverse  than  the  aerial ;  but  they  may  all  be  reduced 
to  a  few  principal  types.  They  are  perfectly  distinguishable  from 
roots  by  producing  regular  buds,  or  by  being  marked  with  scars, 
which  indicate  the  former  insertion  of  leaves,  or  furnished  with 
scales,  which  are  the  rudiments  or  the  vestiges  of  leaves.  All  the 
Scaly  roots  of  the  older  botanists  are  therefore  forms  of  the  stem  or 
branches,  with  which  they  accord  in  every  essential  respect.  So, 
likewise,  what  are  popularly  called  Creeping  roots  are  really  subter- 
ranean branches  ;  such  as  those  of  the  Mint,  and  of  most  Sedges  and 
Grasses.     Some  of  these,  such  as  the  Carex  arenaria  (Fig.  166)  of 


Europe,  render  important  service  in  binding  the  shifting  sands  of 
the  sea-shore.  Others,  like  the  Couch-Grass,  are  often  very  trouble- 
some to  the  agriculturist,  who  finds  it  next  to  impossible  to  destroy 
them  by  the  ordinary  operations  of  husbandry ;  for,  being  furnished 
with  buds  and  roots  at  every  node,  which  are  extremely  tenacious  of 
life,  when  torn  in  pieces  by  the  plough,  each  fragment  is  only  placed 
in  the  more  favorable  condition  for  becoming  an  independent  plant. 
The  Nut-Grass  (Cyperus  Hydra),  an  equally  troublesome  pest  to 
the  planters  of  Carolina  and  Georgia,  is  similarly  constituted ;  and 


FIG.  166.     Creeping  subterranean  stem  of  Carex  arenaria. 

FIO.  167.  Rhizoma  of  Diphylleia  cymosa,  showing  six  years'  growth,  and  a  bud  for  the 
seventh  :  a,  the  bud  :  b,  base  of  the  stalk  of  the  current  year  :  c,  scar  left  by  the  decay  of  the 
annual  stalk  of  the  year  before  ;  and  beyond  are  the  scars  of  previous  years. 


106 


THE    STE3I. 


besides,  the  interminable  subterranean  branches  bear  tubers,  or 
reservoirs  of  nutritive  matter,  in  their  course,  which  have  still 
greater  powers  of  vitality,  as  they  contain  a  copious  store  of  food 
for  the  development  of  the  buds  they  bear.     The  name  of 

188.  Rhizoma  or  RootstOCk  is  applied  in  a  general  way  to  all  these 
perennial,  horizontally  elongated,  more  or  less  subterranean,  root- 
like forms  of 
the  stem;  and 
more  particu- 
larly to  those 
that  are  consid- 
erably thick- 
ened by  the  ac- 
163  cumulation    of 

starch  or  other  forms  of  nutritive  matter  in  their  tissue,  such  as  the 
so-called  roots  of  Ginger,  of  the  Iris  or  Flower-de-luce  (Fig.  291),  of 
the  Calamus  or  Sweet  Flag,  and  of  the  Blood- 
root.  They  grow  after  the  manner  of  ordinary 
stems,  advancing  from  year  to  year  by  the 
annual  development  of  a  bud  at  the  apex,  and 
emitting  roots  from  the  under  side  of  the  whole 
surface ;  thus  established,  the  older  portions  die 
and  decay,  as  corresponding  additions  are  made 
to  the  opposite  growing  extremity.  Each  year's 
growth  is  often  marked,  as  in  some  species  of 
Iris  (Fig.  291),  by  a  narrowing  at  the  place  r( 
where  the  growth  of  the  season  is  suspended, 
followed  by  an  enlargement  where  it  recom- 
mences ;  or  else,  as  in  the  curious  Diphylleia  of 
the  Alleghany  Mountains  (Fig.  1G7),  and  the  Polygonatum  or 
Solomon's  Seal  (Fig.  168),  it  is  more  indelibly  stamped  by  an  im- 
pressed circular  scar  (which  has  been  likened  to  the  impression  of  a 
seal),  left  annually,  in  autumn,  by  the  death  and  separation  from  the 
perennial  rootstock  of  the  herbaceous  stalk  of  the  season  which  bore 
the  foliage  and  blossoms.  In  Diphylleia  the  growth  is  so  slow,  and 
the  ascending  stems  so  thick,  that  the  scars  of  successive  years  are 


FIG.  168.    Rootstock  of  Polygonatum  or  Solomon's  Seal,  with  the  terminal  bud,  the  base  of 
the  stalk  of  the  season,  and  three  scars  from  which  the  latter  has  separated  in  as  many  former 


FIG.  169.     The  short  and  upright  rootstock  of  Trillium  erectum,  or  Birthroot,  with  its  ter- 
minal bud. 


ROOTSTOCKS    AND    TUBERS. 


107 


nearly  in  contact  (Fig.  167).  In  the  very  short  and  slow-growing 
rootstock  of  Trillium  (Fig.  169),  the  base  of  the  leaf-bearing  and 
flowering  stem  of  the  season  surrounds  and  covers  the  terminal  bud. 
In  our  common  Dentaria  or  Toothwort,  and  in  Hydrophyllum,  the 
base  of  this  annual  stalk  or  of  the  leafstalks  partakes  in  the  thicken- 
ing, and  persists  as  a  part  of  the  rhizoma,  in  the  form  of  fleshy  scales 
or  tooth-shaped  processes.  In  other  scaly  rootstocks,  these  persist- 
ent bases  of  the  leaves  are  thin,  and  more  like  bud-scales,  and  slowly 
decay  after  a  year  or  two.  All  such  markings  are  vestiges  of  leaves, 
&c,  or  the  scars  from  which  they  have  fallen  or  decayed  away,  and 
indicate  the  nodes.  They  show  that  the  body  that  bears  them 
belongs  to  the  stem ;  and  not  to  the  root,  which  is  wholly  leafless. 
Root-stocks  branch,  just  as  other  stems  do,  by  the  development  of 
lateral  buds  from  the  axils  of  their  scales  or  leaves.  They  serve 
as  a  reservoir  of  nourishing  matter,  for  the  maintenance  of  the  an- 
nual growth,  in  the  same  manner  as  do  thickened  roots  (145,  146). 
When  such  subterranean  stems  are  thickened  at  the  apex  only,  they 
produce 

189.  A  Tuber.     This  is  usually  formed  by  the  enlargement  of  the 
growing  bud  of  a  subterranean  branch,  and  the  deposition  of  starch, 


&c.  in  its  tissue.  This  deposit  serves  for  the  nourishment  of  the 
buds  (eyes)  which  it  involves,  when  they  develop  the  following  year. 
The   common   Potato  offers   the  most  familiar  example ;  and  it  is 

FIG.  170.  Base  of  the  stem  of  the  Jerusalem  Artichoke  (Uelianthus  tuberosus),  with  its 
tubers. 

FIG.  171.  A  monstrous  branch  or  bud  of  the  Potato,  aboye  ground,  showing  a  transition 

to  the  tuber.  (From  the  Gardener's  Chronicle.) 


108 


THE    STEM. 


very  evident  on  inspection  of  the  growing  plant,  that  the  tubers 
belong  to  branches,  and  not  to  the  roots.     The  nature  of  the  potato 


is  also  well  shown  by  an  accidental  case  (Fig.  171), 
of  the  buds  or  branches  above  ground  thickened  and 
manifested  a  strong  tendency  to  develop  in  the  form 
of  tubers.  By  heaping  the  soil  around  the  stems, 
the  number  of  tuberiferous  branches  is  increased. 
The  Jerusalem  Artichoke  also  affords  a  familiar  il- 
lustration of  the  tuber  (Fig.  170).  A  tuber  of  a 
rounded  form,  and  with  few  buds,  or  a  rhizoma 
somewhat  shorter  and  thicker  than  that  in  Fig.  169, 
effects  a  transition  to 

190.  A  Corm  (Cormus),  or  Solid  Bulb.  This  is  a 
fleshy  subterranean  stem,  of  a  rounded  or  oval  figure 
and  a  compact  texture ;  as  in  the  Arum  or  Indian 
Turnip  (Fig.  175),  the  Colchicum,  the  Crocus  (Fig. 
180,  181,  182),  the  Cyclamen*  &c  Corms  have 
been  termed  solid  bulbs.  But  the  principal  bulk  of 
a  true  bulb  consists  not  of  stem  but  of  leaves. 


*  The  flattened  conn  of  Cyclamen  originates  from  the  dilatation  of  the  radicle 
itself.  In  the  Turnip,  Beet,  and  Radish  (Fig.  138),  this  also  enlarges  with  the 
proper  root,  the  upper  part  of  which  accordingly  partakes  of  the  nature  of  the  stem. 

FIG.  172.  The  scaly  bulb  of  a  Lily.  173.  A  vertical  section  of  the  same,  forming  the  an- 
nual stalk.    174.  Axillary  bulblets  of  Lilium  bulbiferum.    175.  Corm  of  Arum  triphyllum. 

FIG.  176.  A  radical  leaf  of  the  White  Lily,  with  its  base  thickened  into  a  bulb-scale,  cut 
across  below  to  show  its  thickness. 


BULBS    AND    BULBLETS. 


109 


191.  A  Bulb  is  a  permanently  abbreviated  stem,  mostly  shorter 
than  broad,  and  clothed  with  scales,  which  are  imperfect  and  thick- 
ened leaves,  or  more  commonly  the  thickened  and  persistent  bases 
of  ordinary  leaves  (Fig.  176).  In  other  words,  it  is  a  scaly  and 
usually  subterranean  bud,  with  thickened  scales,  and  a  depressed 
axis  which  never  elongates.  Its  centre  or  apex  develops  upward 
the  herbaceous  stalk,  foliage,  and  flowers  of  the  season,  and  beneath 
emits  roots.  In  the  bulb,  the  thickening  by  the  deposition  of  nutri- 
tive matter,  stored  for  future  use,  takes  place  in  the  leaves  or  scales 
it  bears,  instead  of  the  stem  itself,  as  in  the  preceding  forms.  The 
scales  are  sometimes  separate,  thick,  and  narrow,  as  in  the  Scaly 
bulb  of  the  Lily  (Fig.  172)  ;  sometimes  broad  and  in  concentric 
layers,  as  in  the  Tunicated  bulb  of  the  Onion  (Fig.  177). 

192.  BulbletS  are  small  aerial  bulbs,  or  buds  with  fleshy  scales, 
which  arise  in  the  axils  of  the  leaves  of  several  plants,  such  as  the 
common  Lilium  bulbiferum  of  the  gardens  (Fig.  174),  and  at  length 
separate  spontaneously,  falling  to  the  ground,  where  they  strike  root, 
and  grow  as  independent  plants.  In  the  Onion,  and  other  species  of 
Album,  bulblets  are  often  produced  in  place  of  flower-buds.  These 
plainly  show  the  identity  of  bulbs  with  buds. 

193.  All  these  extraordinary,  no  less  than  the  ordinary,  forms 


FIG.  177.    Section  of  a  tunicated  bulb  of  the  Onion. 

FIG.  178.     Vertical  section  of  the  bulb  of  the  Tulip,  showing  its  stem  (a)  and  buds  (b,  c). 
FIG.  179.    Bulb  of  a  Garlic,  with  a  crop  of  young  bulbs. 
FIG.  180.     Vertical  section  of  the  corm  of  Crocus  :  a,  new  buds. 

FIG.  181.     Vertical  section  of  the  corm  of  Colchicum,  with  the  withered  corm  of  the  pre- 
ceding (a),  and  the  forming  one  (c)  for  the  ensuing  year. 

10 


110 


THE    STEM. 


of  the  stem,  grow  and  branch,  or  multiply,  by  the  development  of 
terminal  and  axillary  buds.  This  is  perfectly  evident  in  the  rhizoma 
and  tuber,  and  is  equally  the  case  in  the  corm  and  bulb.  The  stem 
of  the  bulb  is  usually  reduced  to  a  mere  plate  (Fig.  178,  a),  which 
produces  roots  from  its  lower  surface,  and  leaves  or  scales  from  the 
upper  surface.  Besides  the  terminal  bud  (c),  which  usually  forms 
the  flower-stem,  lateral  buds  (b,  b)  are  produced  in  the  axils  of  the 
leaves  or  scales.  One  or  more  of  these  may  develop  as  flowering 
stems  the  next'  season,  and  thus  the  same  bulb  survive  and  blossom 
from  year  to  year ;  or  these  axillary  buds  may  themselves  become 
bulbs,  feeding  on  the  parent  bulb,  which  in  this  way  is  often  con- 
sumed by  its  own  offspring,  as  in  the  Garlic  (Fig.  179)  ;  or,  finally 
separating  from  the  living  parent,  just  as  the  bulblets  of  the  Tiger 
Lily  fall  from  the  stem,  they  may  form  so  many  independent  indi- 
viduals. So  the  corm  of  the  Crocus  (Fig. 
182,  182")  produces  one  or  more  new  ones, 
which  feed  upon  and  exhaust  it,  and  take  its 
place ;  and  the  shrivelled  remains  of  the  old 
corm  may  be  found  underneath  the  new,  the 
next  season.  The  corm  of  Colchicum  (Fig. 
181)  produces  a  new  bud  on  one  side  at  the 
base,  and  is  consumed  by  it  in  the  course  of 
the  season ;  the  new  one,  after  flowering  by 
its  terminal  bud,  is  in  turn  consumed  by  its 
own  offspring;  and  so  on.  In  Fig.  181,  we 
have  at  one  view,  a,  the  dead  and  shrivelled 
corm  of  the  year  preceding ;  b,  that  of  the 
present  season  (a  vertical  section) ;  and  c, 
*S2  °  the  nascent  bud  for  the  growth  of  the  ensuing 

season.  Many  of  the  forms  which  the  stem  assumes  when  above 
ground  differ  as  much  from  the  ordinary  appearance  as  do  any  of 
these  subterranean  kinds,  and,  in  fact,  imitate  their  peculiarities ;  as, 
for  example,  the  globular  Melon-Cactus  and  Mamillaria,  the  colum- 
nar Cereus,  and  the  jointed  Opuntia  or  Prickly  Pear.  These  are 
remarkably 

194.  Consolidated  Forms  Of  Vegetation.     While  ordinary  plants  are 
constructed  on  the  plan  of  great  expansion  of  surface,  these  are 

FIG.  182.  Corm  of  Crocus,  the  few  thin  enveloping  scales  removed,  showing  the  shrivelled 
vestige  of  the  last  year's  corm  at  the  base,  and  buds  developing  into  new  ones  on  various 
parts  of  its  surface.  182Q.  Vertical  section  of  a  similar  corm,  with  a  terminal  and  one  lateral 
bud. 


CONSOLIDATED  FORMS  OF  VEGETATION.         Ill 

formed  on  the  plan  of  the  least  possible  amount  of  surface  in  pro- 
portion to  their  bulk.  A  green  rind  serves  the  purpose  of  foliage ; 
but  the  surface  is  as  nothing  compared  with  an  ordinary  leafy  plant 
of  the  same  amount  of  vegetable  material.  This  consolidation  is 
carried  to  the  extreme  in  the  Melon-Cactus,  Mamillaria,  and  the 
like,  of  globular  or  corm-like  shapes  ;  their  spherical  figure  being 
that  which  exposes  the  least  possible  part  of  the  bulk  to  the  air. 
Such  plants  are  evidently  adapted  and  designed  for  very  dry 
regions;  and  in  such  only  are  they  naturally  found.  Similarly, 
bulbous  and  corm-bearing  plants,  and  the  like,  are  a  form  of  vege- 
tation which  in  the  growing  season  may  in  the  foliage  expand  a 
large  surface  to  the  air  and  light,  while  during  the  period  of  rest 
the  living  vegetable  is  reduced  to  a  globular  or  other  form  of  the 
least  surface ;  and  this  is  protected  by  its  outer  coats  of  dead  and 
dry  scales,  as  well  as  by  its  subterranean  situation ;  —  thus  exhibit- 
ing another  and  very  similar  adaptation  to  a  season  of  drought. 
And  such  plants  mainly  belong  to  countries  (such  as  Southern 
Africa,  and  parts  of  the  interior  of  Oregon  and  California)  which 
have  a  long  hot  season,  during  which  little  or  no  rain  falls,  when, 
their  stalks  and  foliage  above  and  their  roots  beneath  being  early 
cut  off  by  drought,  the  plants  rest  securely  in  their  compact  bulbs, 
filled  with  nourishment,  and  retain  their  moisture  with  great 
tenacity,  until  the  rainy  season  returns.  Then  they  shoot  forth 
leaves  and  flowers  with  wonderful  rapidity,  and  what  was  perhaps 
a  desert  of  arid  sand  becomes  green  with  foliage  and  gay  with  blos- 
soms, almost  in  a  day.  This  will  be  more  perfectly  understood 
when  the  nature  and  the  use  of  foliage  shall  have  been  more  fully 
considered. 


Sect.   IV.      The  Internal    Structure   op  the   Stem  in 
General. 

195.  Having  considered  the  various  external  forms  and  appear- 
ances which  the  stem  exhibits,  and  its  mode  of  increase  in  length, 
our  attention  may  now  be  directed  to  its  internal  structure,  and  its 
mode  of  increase  in  diameter. 

196.  The  stem  embraces  in  its  composition  the  various  forms  of 
elementary  tissue  that  have  already  been  described  (Chap.  I.,  Sect. 
II.,  III.)  ;   namely,  ordinary  cells,  woody  fibre,  and  vessels.     At 


112  THE    STEM. 

first,  indeed,  it  consists  entirely  of  parenchyma  (51),  which  pos- 
sesses much  less  strength  and  tenacity  than  woody  tissue,  and  is 
therefore  inadequate  to  the  purposes  for  which  the  stem,  in  all  the 
higher  plants,  is  destined.  The  stem  of  a  Moss  or  a  Liverwort  is, 
in  fact,  composed  of  ordinary  cellular  tissue  alone ;  and  is  therefore 
weak  and  brittle,  well  enough  adapted  to  plants  of  humble  size, 
but  not  for  those  which  attain  any  considerable  height.  Accord- 
ingly, as  soon  as  the  stems  of  Phamogamous  plants  begin  to  grow, 
and  in  proportion  as  the  leaves  are  developed,  woody  mingled  with 
vascular  tissue  is  introduced,  to  afford  the  requisite  toughness  and 
strength,  and  to  facilitate  the  rise  of  the  ascending  sap.  If  the 
wood  accumulates  only  to  moderate  extent  in  proportion  to  the 
parenchyma,  the  stem  remains  herbaceous  (174)  ;  if  it  predominates 
and  continues  to  accumulate  from  year  to  year,  the  proper  woody 
trunk  of  a  shrub  or  tree  is  formed. 

197.  The  cellular  part  of  the  stem  grows  with  equal  readiness, 
in  whatever  direction  the  forces  of  vegetation  act.  It  grows  verti- 
cally, to  increase  the  stem  in  length,  and  horizontally,  to  increase 
its  diameter.  Into  this  the  elongated  cells  that  form  the  woody 
tissue  and  ducts  are  introduced  vertically ;  they  run  lengthwise 
through  the  stem  and  branches.  Hence,  the  latter  has  been  called 
the  longitudinal,  vertical,  or  perpendicular  system  (56,  64) ;  and 
the  cellular  part,  the  horizontal  system  of  the  stem.  Or  the  stem 
may  be  compared  to  a  web  of  cloth;  the  cellular  system  forming 
the  woof,  and  the  woody,  the  warp. 

198.  The  diversities  in  the  internal  structure  of  the  stem  are 
principally  owing  to  the  different  modes  in  which  the  woody  or 
vertical  system  is  imbedded  in  the  cellular.  These  diversities  are 
reducible  to  two  general  plans ;  upon  one  or  the  other  of  which  the 
stems  of  all  Flowering  plants  are  constructed.  Not  only  is  the 
difference  in  structure  quite  striking,  especially  in  all  stems  more 
than  a  year  old,  but  it  is  manifested  in  the  whole  vegetation  of  the 
two  kinds  of  plants,  and  indicates  the  division  of  Phamogamous 
plants  into  two  great  classes,  recognizable  by  every  eye ;  which, 
in  their  fully  developed  forms,  may  be  represented,  one  by  the  Oak 
and  other  trees  of  our  climate,  the  other  by  the  Palm  (Fig.  181). 

199.  The  difference  between  the  two,  as  to  the  structure  of  their 
stems,  is  briefly  and  simply  this.  In  the  first,  the  woody  system  is 
deposited  in  annual  concentric  layers  between  a  central  pith  and  an 
exterior  bark;  so  that  a  cross-section  presents  a  series  of  rings  or 


ITS  INTERNAL  STRUCTURE.  113 

circles  of  wood,  surrounding  each  other  and  a  distinct  pith,  and  all 
surrounded  by  a  separable  bark.  This  is  the  plan,  not  only  of  the 
Oak,  but  of  all  the  trees  and  shrubs  of  the  colder  climates.  In  the 
second,  the  woody  system  is  not  disposed  in  layers,  but  consists  of 
separate  bundles  or  threads  of  woody  fibre,  &c,  running  through  the 
cellular  system  without  apparent  order ;  and  presenting  on  the  cross- 
section  a  view  of  the  divided  ends  of  these  threads  in  the  form  of 
dots,  diffused  through  the  whole ;  but  with  no  distinct  pith,  and  no 
bark  which  is  at  any  time  readily  separable  from  the  wood.  The 
appearance  of  such  a  stem,  both  on  the  longitudinal  and  the  cross- 
section,  is  shown  in  Fig.  183  ;  it  may  also  be  examined  in  the  Cane 
or  Rattan,  the  Bamboo,  and  in  the  annual  stalk  of  Indian  Corn  or 
of  Asparagus.  That  of  ordinary  wood  of  the  first  sort  is  too  famil- 
iar to  need  a  pictorial  illustration. 

200.  Exogenous  Structure.  The  stem,  in  the  first  case,  increases 
in  diameter  by  the  annual  formation  of  a  new  layer  of  wood,  which 
is  deposited  between  the  preceding  layer  and  the  bark ;  that  is,  the 
wood  increases  by  annual  additions  to  its  outside.  Hence,  such 
stems  are  said  to  be  Exogenous  ;  and  plants  whose  stems  grow  in 
this  way  are  called  Exogenous  Plants,  or  briefly  Exogens  ; 
that  is,  as  the  term  literally  signifies,  outside-growers. 

201.  Endogenous  Structure.  In  the  second  case,  the  new  woody 
matter  is  intermingled  with  the  old,  or  deposited  towards  the  centre, 
which  becomes  more  and  more  occupied 

with  the  woody  threads  as  the  stem  grows 
older ;  and  increase  in  diameter,  so  far  as 
it  depends  on  the  formation  of  new  wood, 
generally  takes  place  by  the  gradual  dis- 
tention of  the  whole.  Accordingly,  these 
stems  are  said  to  exhibit  the  Endoge- 
nous structure  or  growth ;  and  such  plants  1S3 
are  called  Endogenous  Plants,  or  Endogens  ;  literally,  tiiside- 
groivers. 

202.  The  two  great  classes  of  Phaenogamous  plants,  indicated  by 
this' difference  in  the  stem,  are  distinguishable  even  in  the  embryo 
state,  by  differences  quite  as  marked  as  those  which  prevail  in  their 
Avhole  port  and  aspect.  The  embryo  of  all  plants  that  have  en- 
dogenous stems  bears  only  a  single  cotyledon ;  hence,  Endogens  are 
also  called  Monocotyledonous  Plants  (128).     The  embryo  of 

FIG.  183.     Section  (longitudinal  and  transverse)  of  a  Palm-stem. 

10* 


114 


THE    STEM. 


plants  with  exogenous  stems  bears  a  pair  of  cotyledons  and  unfolds 
a  pair  of  seed-leaves  in  germination  (Fig.  106, 125)  ;  hence,  Exogens 
are  likewise  called  Dicotyledonous  Plants. 


Sect.  V.    The  Endogenous  or  Monocotyledonous  Stem. 


208.  Endogens,  or  Inside-growers,  although  they  have  many 
humble  representatives  in  Northern  climes,  yet  only  attain  their  full 
characteristic  devel- 
opment, and  display 
their  noble  arbores- 
cent forms,  under  a 
tropical  sun.  Yet 
Palms  —  the  type  of 
the  class  —  do  ex- 
tend as  far  north  in 
this  country  as  the 
coast  of  North  Caro- 
lina (the  natural  lim- 
it of  the  Palmetto, 
Fig.  184)  ;  while  in 
Europe  the  Date 
and  the  Chamasrops 
thrive  in  the  warm- 
er parts  of  the 
European  shore  of 
the  Mediterranean. 
The  manner  of  their 
growth  gives 
them  astrik-  VV".,/.V 
ing  appear- 
ance ;  their  t  j 
trunks  being 
unbranehed, 

cylindrical  columns,  rising  majestically  to  the  height  of  from  thirty 
to  one  hundred  and  fifty  feet,  and  crowned  at  the  summit  with  a 
simple  cluster  of  peculiar  foliage.  Then*  internal  structure  is  equal- 
ly different  from  that  of  ordinary  wood. 

FIG.  184.    The  Chamaerops  Palmetto,  in  various  stages,  and  the  Yucca  Dracouis. 


M*^m 


ENDOGENOUS    STRUCTURE. 


115 


204.  The  stem  of  an  Endogen,  as  already  explained  (199),  offers 
no  manifest  distinction  into  bark,  pith,  and  wood ;  and  the  latter  is  not 
composed  of  concentric  rings  or  layers.  But  it  consists  of  bundles  of 
woody  and  vascular  tissue,  in  the  form  of  fibres  or  threads,  which  are 
imbedded,  with  little  apparent  regularity,  in  cellular  tissue ;  and  the 
whole  is  enclosed  in  an  integument,  which  does  not  strictly  resemble 
the  bark  of  an  Exogenous  plant,  inasmuch  as  it  does  not  increase 
by  layers,  and  is  never  separable  from  the  wood.  The  fibrous 
bundles  which  compose  the  wood,  and  which  consist  of  a  mass  of 
woody  fibres  surrounding  several  vessels,  are  distributed  throughout 
the  cellular  system  of  the  stem,  but  most  abundantly  towards  the 
circumference.  Each  bundle  usually  contains  all  the  elements  of 
the  wood  of  the  exogenous  stem ;  namely,  vessels,  proper  woody 
tissue,  and  bast-cells.  The  bundles  often  may  be  traced  directly 
from  the  base  of  the  leaves  down  through  the  stem,  some  of  them 
to  the  roots  in  a  young  plant,  while  others,  curving  outwards,  lose 
themselves  in  the  cortical  integument, 

or  rind.  As  the  stem  increases,  new 
bundles,  springing  from  the  bases  of 
more  recently  developed  leaves,  are  at 
first  directed  towards  the  centre  of  the 
stem,  along  which  they  descend  for 
some  distance,  growing  more  slender 
in  their  course,  and  then,  curving  out- 
wards, mostly  terminate  hi  the  rind. 
It  is  partly  in  consequence  of  the  co- 
hesion of  these  obliquely  descending 
fibres  to  the  false  bark,  that  the  latter 
cannot,  as  in  Exogens,  be  separated 
from  the  wood  beneath.     The  manner 

in  which  the  woody  threads  are  consequently  interwoven  is  shown 
in  Fig.  185.  The  Palm-like  Yuccas  of  the  Southern  States  offer 
beautiful  illustrations  of  the  kind. 

205.  Endogenous  stems,  instead  of  having  the  oldest  and  hardest 
wood  at  the  centre  and  the  newest  and  softest  at  the  circumference, 
as  in  ordinary  trees,  are  softest  towards  the  centre  and  most  compact 
at  the  circumference.  They  increase  in  diameter  with  the  increas- 
ing number  of  woody  bundles  (which  multiply  as  new  leaves  are 


FIG.  185.     Vertical  ami  transverse  section  of  a  young  endogenous  stem,  showing  the  curv- 
ing of  the  fibres. 


116  THE    STEM. 

produced),  as  long  as  the  rind  is  capable  of  distention.  In  some 
instances,  as  in  the  arborescent  Yuccas  and  the  Dracaenas  or  Dragon- 
trees,  the  rind  remains  soft  and  capable  of  unlimited  growth ;  but  in 
the  Palms,  and  in  most  woody  Endogens,  it  soon  indurates,  and  the 
stem  consequently  increases  no  further  in  diameter.  The  wood  of 
the  lower  part  of  such  stem  is  more  compact  than  the  upper,  being 
more  filled  with  woody  bundles,  and  the  rind  is  firmer,  from  the 
greater  number  of  ligneous  fibres  which  terminate  in  it,  and  from 
its  proper  induration. 

206.  Palms  generally  grow  from  the  terminal  bud  alone,  and 
perish  if  this  bud  be  destroyed ;  they  grow  slowly,  and  bear  their 
foliage  in  a  cluster  at  the  summit  of  the  trunk,  which  consequently 
forms  a  simple  cylindrical  column.  But  in  some  instances  two  or 
more  buds  develop,  and  the  stem  branches,  as  in  the  Doum  Palm  of 
Upper  Egypt,  and  in  the  Pandanus,  or  Screw-Pine  (Fig.  140), 
which  belongs  to  a  family  allied  to  Palms :  in  such  cases  the 
branches  are  cylindrical.  But  when  lateral  buds  are  freely  devel- 
oped (as  in  the  Asparagus),  or  the  leaves  are  scattered  along  the 
stem  or  branches  (as  in  the  Bamboo,  Maize,  &c),  these  taper  up- 
wards, just  as  in  Exogens.  A  particular  comparison  of  the  structure 
and  growth  of  the  Endogenous  stem  with  the  Exogenous  cannot  be 
instituted  until  the  latter  is  explained  in  detail. 


Sect.  VI.    The  Exogenous  or  Dicotyledonous  Stem. 

207.  Since  the  Exogenous  class  is  by  far  the  larger  in  every  part 
of  the  world,  and  embraces  all  the  trees  and  shrubs  with  which  we 
are  familiar  in  the  cooler  climates,  the  structure  of  this  kind  of  stem 
demands  more  detailed  notice.  To  obtain  a  true  and  clear  idea  of 
its  internal  structure,  we  should  commence  at  its  origin  and  follow 
the  course  of  development. 

208.  In  the  embryo,  or  at  least  at  some  period  antecedent  to 
germination,  the  rudimentary  stem  is  entirely  composed  of  paren- 
chyma. But  as  soon  as  it  begins  to  grow,  some  of  the  cells  begin  to 
lengthen  into  tubes,  to  be  marked  with  transverse  bars  or  spiral 
lines,  and  thus  give  rise  to  ducts  or  vessels  (57  -  60)  ;  these  form  a 
small  and  definite  number  of  bundles  or  threads,  say  four  equidistant 
ones  in  the  first  instance,  as  in  the  Sugar  Maple :  surrounding  these, 
other  slender  cells  of  smaller  calibre,  and  destitute  of  markings, 


EXOGENOUS  STRUCTURE. 


117 


soon  appear,  and  form  the  earliest  woody  tissue.  As  the  rudiments 
of  the  next  internode  and  its  leaves  appear,  two  or  four  additional 
threads  of  vascular  tissue  appear  in  the  stem  below,  in  the  paren- 
chyma between  the  earliest  ones,  and  are  equally  surrounded  with 
forming  woody  tissue.  At  an  early  stage,  therefore,  the  developing 
stem  is  seen  to  be  traversed  by  several  bundles  of  woody  tissue,  with 
some  vessels  imbedded ;  and  these,  as  they  increase  and  enlarge,  run 
together  so  as  to  make  up  a  woody  zone  (or,  as  seen  in  the  cross- 
section,  a  ring),  enclosing  the  central  part  of  the  pai*enchyma  within 
it,  and  itself  enclosed  by  the  external  parenchyma.  Thus  a  zone  or 
layer  of  wood  is  formed,  which  is  so  situated  in  the  original  homo- 
geneous cellular  system  as  to  divide  it  into  two  parts ;  namely,  a 
central  portion,  which  forms  the  pith,  and  an  exterior  portion,  which 
belongs  to  the  bark.  The  whole  is  of  course  invested  by  the  skin 
or  epidermis,  which  covers  the  entire  surface  of  the  plant.  The 
way  in  which  the  layer  of  wood  thus  originates  is  somewhat  rudely 
illustrated  by  the  annexed  diagrams  (Fig.  186-  188).     The  several 


woody  masses,  or  wedges,  are  separated  from  each  other  by  lines  or 
bands  of  the  original  cellular  tissue,  which  pass  from  the  pith  to  the 
bark,  and  which  necessarily  become  narrower  and  more  numerous  as 
the  woody  bundles  or  wedges  increase  in  size  and  number.  These 
bands  are  the 

209.  Medullary  Rays.  These  form  the  radiating  lines  that  the 
cross-section  of  most  exogenous  wood  so  plainly  exhibits,  especially 
that  of  the  Oak,   Plane,  &c.     They  consist  of  parenchyma,  more 


FIG.  186.  Plan  of  a  cross-section  of  a  forming  seedling  stem,  showing  the  manner  in  which 
the  young  wood  is  imbedded  in  the  cellular  system. 

FIG.  187.  The  same  at  a  later  period,  the  woody  bundles  increased  so  as  nearly  to  fill  the 
circle. 

FIG.  188.  The  same  at  the  close  of  the  season,  where  the  wood  has  formed  a  complete 
circle,  separating  the  pith  from  the  bark,  except  that  they  are  still  connected  by  narrow  por- 
tions of  the  cellular  system  (the  medullary  rays)  which  radiate  from  the  pith  to  the  bark. 


118 


THE    STEM. 


or  less  flattened  by  the  pressure  of  the  woody  wedges,  and  they 
serve  to  keep  up  the  communication  between  the  pith  and  the 
bark. 

210.  The  First  Year's  Growth  of  an  exogenous  stem  accordingly  con- 
sists of  three  principal  parts,  viz. :  1st,  a  central  cellular  portion,  or 
Pith;  2d,  a  zone  of  Wood;  and  3d,  an  exterior  cellular  portion,  or 

Bark.  These  several 
parts  are  displayed 
in  Fig.  189-191,  as 
they  occur  in  a  woody 
stem  a  year  old. 

211.  The  Pith  (Me- 
dulla) consists  en- 
tirely of  soft  cellular 
tissue,  or  parenchy- 
ma* (51),  which  is 
at  first  gorged  with 
sap.  Many  stems 
expand  so  rapidly  in 
diameter  during  their 
early  growth,  that 
they  become  hollow, 
the  pith  being  torn 
away  by  the  disten- 
tion, and  its  remains 
forming  a  mere  lin- 
ing to  the  cavity. 
In  the  "Walnut  and 
the  Poke  (Phytolac- 


*  In  rare  instances  a  few  threads  of  woody  tissue  and  vessels  are  found  dis- 
persed through  the  pith,  presenting  a  somewhat  remarkable  anomaly.  This 
occurs  in  Aralia  racemosa,  and  more  strikingly  in  Oxybaphus,  Mirabilis  or 
Four-o'clock,  and  other  Nyctaginaceae. 

FIG.  189.  Longitudinal  and  transverse  section  of  a  stem  of  the  Soft  Maple  (Acer  dasycar- 
pum),  at  the  close  of  the  first  year's  growth  ;  of  the  natural  size. 

FIG.  190.  Portion  of  the  same,  magnified,  showing  the  cellular  pith,  surrounded  by  the 
wood,  and  that  enclosed  by  the  bark. 

FIG.  191.  More  magnified  slice  of  the  same,  reaching  from  the  bark  to  the  pith  :  a,  part  of 
the  pith  ;  b,  vessels  of  the  medullary  sheath  ;  c,  the  wood  ;  rfrf,  dotted  ducts  in  the  wood  ;  ee, 
annular  ducts  ;  f,  the  liber,  or  inner  fibrous  bark  ;  g,  the  cellular  envelope,  or  green  bark  ;  A, 
the  corky  envelope  ;  i,  the  skin  or  epidermis  ;  k,  one  of  the  medullary  rays,  seen  on  the  trans- 
verse section. 


EXOGENOUS  STRUCTURE. 


119 


ca)  it  is  early  separated  into  a  series  of  horizontal  plates.  As  the 
stem  groAvs  older  the  pith  becomes  dry  and  light,  its  cells  filled  with 
air  only ;  and  then  it  is  of  no  further  use  to  the  plant. 

212.  Tlie  Wood  consists  of  proper  Avoody  tissue  (53),  among  which 
the  vascular  is  more  or  less  copiously  mingled,  principally  in  the 
form  of  dotted  ducts  (Fig.  191,  d),  or  occasionally  some  annular 
ducts  (e),  &c.  The  dotted  ducts  are  of  so  considerable  calibre,  that 
they  are  conspicuous  to  the  naked  eye  in  many  ordinary  kinds  of 
Avood,  especially  AA'here  they  are  accumulated  in  the  inner  portion  of 
each  layer,  as  in  the  Chestnut  and  Oak.  In  the  Maple,  Plane,  &c, 
they  are  rather  equably  scattered  through  the  annual  layer,  and  are 
of  a  size  so  small,  that  they  are  not  distinguishable  by  the  naked  eye. 
—  Next  the  pith,  i.  e.  in  the  very  earliest  formed  part  of  the  AATood, 
some  spiral  ducts  are  uniformly  found  (Fig.  191,  b),  and  this  is  the 
only  part  of  the  exogenous  stem  in  whieh  these  ordinarily  occur. 
They  may  be  detected  by  breaking  a  woody  tA\rig  in  tAA'o,  after  divid- 
ing the  bark  and  most  of  the  AArood  by  a  circular  incision,  and  then 
pulling  the  ends  gently  asunder,  AA'hen  their  spirally  coiled  fibres  are 
readily  draAvn  out  as  gossamer  threads.  As  these  spiral  ducts  form 
a  circle  immediately  surrounding  the  pith,  they  form  AA'hat  has  been 
termed  the  Medullary  Sheath.  This  is  no  special  organ,  and 
hardly  requires  a  special  name,  since  it  merely  represents  the  earli- 
est-formed vascular  tissue  of  the  stem. 

213.  The  vertical  section  in  Fig.  191  divides  one  of  the  woody 
wedges ;  and  therefore  the  medullary  rays  do  not  appear.     But  in 


FIG.  192.  Vertical  section  through  the  wood  of  a  branch  of  the  Maple,  a  year  old  ;  so  as  to 
show  one  of  the  medullary  rays,  passing  transversely  from  the  pith  (p)  to  the  bark  (b):  mag- 
nified. But  a  section  can  seldom  be  made  so  as  to  show  one  unbroken  plate  stretching  across 
the  wood,  as  in  this  instance. 

FIG.  193.    A  vertical  section  across  the  ends  of  the  medullary  rays  ;  magnified. 


120  the  stem:. 

the  much  more  magnified  Fig.  192,  the  section  is  made  so  as  to 
show  the  surface  of  one  of  these  plates,  and  one  of  the  Medullary 
Rays  passing  horizontally  across  it,  connecting  the  pith  (p)  with 
the  bark  (b).  These  medullary  rays  form  the  silver-grain,  (as  it 
is  termed,)  which  is  so  conspicuous  in  the  Maple,  Oak,  &c,  and 
which  gives  the  glimmering  lustre  to  many  kinds  of  Avood  when  cut 
in  this  direction.  But  a  section  made  as  a  tangent  to  the  circum- 
ference, and  therefore  perpendicular  to  the  medullary  rays,  brings 
their  ends  to  A'ieAV,  as  in  Fig.  193 ;  much  as  they  appear  Avhen  seen 
on  the  surface  of  a  piece  of  Avood  from  which  the  bark  is  stripped. 
They  are  here  seen  to  be  composed  of  parenchyma,  and  to  represent 
the  horizontal  system  of  the  Avood,  or  the  woof,  into  which  the  ver- 
tical Avoody  fibre,  &c,  or  ivarp,  is  interwoven.  The  inspection  of  a 
piece  of  oak  or  maple  A\rood  at  once  sIioavs  the  pertinency  of  this 
illustration. 

214.  The  Bark,  in  a  stem  of  a  year  old,  must  next  be  considered. 
At  first  it  consists  of  simple  parenchyma,  undistinguishable  from 
that  of  the  pith,  except  that  it  assumes  a  green  color  when  exposed 
to  the  light,  from  the  production  of  chlorojihyll  (92)  in  its  cells.  But 
during  the  formation  of  the  Avood  of  the  season,  an  analogous  forma- 
tion occurs  in  the  bark.  The  inner  portion,  next  the  Avood,  has 
woody  tissue  formed  in  it,  and  becomes 

215.  The  Liber,  or  Inner  Bark  (Fig.  191,/).  The  fibre-like  cells, 
which  give  to  the  inner  bark  of  those  plants  that  largely  contain 
them  its  principal  strength  and  toughness,  are  of  the  kind  already 
described  under  the  name  of  bast-cells  or  bast-tissue  (55).  They  are 
remarkable  for  their  length,  flexibility,  and  the  great  thickness  of 
their  Avails.  They  form  in  bundles,  or  in  bands  separated  by  exten- 
sions of  the  medullary  rays,  one  accordingly  corresponding  to  each 
of  the  Avoody  plates  or  Avedges ;  or  sometimes  (as  in  Negundo,  Fig. 
194,  195)  they  are  confluent  into  an  unbroken  circle  round  the 
Avhole  circumference.  Complete  and  well-developed  liber,  like  that  of 
the  BassAVood,  consists  of  three  elements,  viz.:  1.  bast-cells  or  fibres  ; 
2.  large  and  more  or  less  elongated  cells,  Avith  thinner  Avails  variously 
marked  Avith  transparent  spots,  appearing  like  perforations,  and 
usually  traversed  by  an  exceedingly  minute  net-work ;  and  3.  cells 
of  parenchyma.  The  liber  has  received  the  technical  name  of 
Endophlceuai  (literally  inner  bark).  In  most  Avoody  stems  the 
exterior  part  of  the  bark,  in  Avhich  no  woody  tissue  occurs,  is  early 
distinguishable  into  tAvo  parts,  an  inner  and  an  outer.     The  former  is 


EXOGENOUS  STRUCTURE. 


121 


216.  The  Cellular  Envelope,  or  Green  Layer  (Fig.  191,  g),  also  called, 
from  its  intermediate  position,  the  Mesophloeum.  This  is  com- 
posed of  loose  parenchyma,  with  thin  walls,  much  like  the  green 
pulp  of  leaves,  and  containing  an  equal  abundance  of  chlorophyll. 
It  is  the  only  part  of  the  bark  that  retains  a  green  color.  In  woody 
steins  this  is  soon  covered  with 

217.  The  Corky  Envelope,  or  Epiphlosum  (Fig.  191,  b),  which 
gives  to  the  twigs  of  trees  and  shrubs  the  hue  peculiar  to  each  spe- 
cies, generally  some  shade  of  ash-color  or  brown,  or  occasionally  of 
much  more  vivid  tints.  It  is  this  tissue,  which,  taking  an  unusual 
development,  forms  the  cork  of  the  Cork-Oak,  and  those  corky  ex- 
pansions of  the  bark  which  are  so  conspicuous  on  the  branches  of 


Wmmm 


r?  o 

m 


FIG.  194.  Portion  of  a  transverse  section,  and  195,  a  corresponding  vertical  section,  magni- 
fied, reaching  from  the  pith,p,  to  the  epidermis,  e,  of  a  stem  of  Negundo,  a  year  old  :  B,  the 
bark  ;  W,  the  wood  ;  and  C,  the  cambium-layer,  as  found  in  February.  The  references  are  in 
the  text  above  ;  except  mr,  portion  of  a  medullary  ray,  seen  on  the  vertical  section,  -where  it 
runs  into  the  pith  :  dd,  dotted  ducts  :  d,  the  inner  part  of  the  cambium-layer,  which  begins 
the  new  layer  of  wood.  In  this  tree,  we  find  a  thick  layer  of  parenchyma  (I)  inside  of  the  bast- 
tissue,  and  therefore  belonging  to  the  liber.  No  bast-tissue  is  formed  in  it  the  second  year. 
11 


122  THE    STEM. 

the  Sweet  Gum  (Liquidambar),  and  on  some  of  our  Elms  (Ulmus 
alata  and  racemosa) .  It  also  forms  the  paper-like,  exfoliating  layers 
of  Birch-bark.  It  is  composed  of  laterally  flattened  parenchymatous 
cells,  much  like  those  of  the  Epidermis  (69,  Fig.  191,  i),  Avhich 
directly  overlies  it,  and  forms  the  skin  or  surface  of  the  stem. 

218.  The  elements  of  an  exogenous  stem  of  a  year  old,  especially 
in  a  woody  plant,  accordingly  are  these,  proceeding  from  the  centre 
towards  the  circumference  :  — 

I.  In  the  Wood  : 

1.  The  Pith,  belonging  to  the  cellular  system  (Fig.  194,  195,  p). 

2.  The  Medullary  Sheath,  ms,    )  which  belong  to  the    woody  or 

3.  The  Layer  of  Wood,  W,  w,    )       longitudinal  system. 

4.  The  Medxdlary  Rays,  mr,  a  part  of  the  cellular  system. 

II.  In  the  Bark  : 

5.  The  Liber,  I ;  its  bast-tissue,  b,  belongs  to  the  woody  system. 

6.  The  Outer  Baric,  belonging  wholly  to  the  cellular  system,  and 

composed  of  two  parts,  viz. :   1st,  the  Green  or  Cellular  En- 
velope, ge,  and  2d,  the  Corky  Envelope,  ce. 

7.  The  Epidermis,  e,  or  skin,  which  invests  the  whole. 

219.  An  herbaceous  stem  does  not  essentially  differ  from  a  woody 
one  of  this  age,  except  that  the  wood  forms  a  less  compact  or  thinner 
zone ;  and  the  whole  perishes,  at  least  down  to  the  ground,  at  the 
close  of  the  season.  But  a  woody  stem  makes  provision  for  contin- 
uing its  growth  the  second  year.  As  the  layer  of  wood  continues  to 
increase  in  thickness  throughout  the  season,  by  the  multiplication  of 
cells  on  its  outer  surface,  between  it  and  the  bark,  and  Avhen  growth 
ceases  this  process  of  cell-multiplication  is  merely  suspended,  so 
there  is  always  a  zone  of  delicate  young  cells  interposed  between  the 
wood  and  the  bark.     This  is  called  the 

220.  Cambium-Layer,  (Fig.  194,  195,  C).  It  is  charged  with  or- 
ganizable  matter  (protoplasm,  dextrine,  &c.)  in  the  form  of  a  mu- 
cilage, which  is  particularly  abundant  in  the  spring  when  growth 
recommences.  This  mucilaginous  matter  was  named  Cambium  by 
the  older  botanists  ;  who  supposed  —  as  is  still  generally  thought  — 
that  the  bark,  then  so  readily  separable,  really  separated  from  the 
wood  in  spring,  that  a  quantity  of  rich  mucilaginous  sap  was  poured 
out  between  them,  and  that  this  sap,  or  cambium,  was  organized 
into  a  tissue,  the  inner  part  becoming  new  wood,  the  outer,  new 
bark.  But  delicate  slices  will  show  that  there  is  then  no  more  inter- 
ruption of  the  wood  and  inner  bark  than  at  any  other  season ;  that 


EXOGENOUS    STRUCTURE.  123 

the  two  are  always  organically  connected  by  an  extremely  delicate 
tissue  of  young  and  vitally  active  cells,  just  in  the  state  in  which 
they  multiply  by  division  (33).  The  bark,  indeed,  is  very  readily 
detached  from  the  wood  in  spring,  because  the  cambium-layer  is  then 
gorged  with  sap ;  but  the  separation  is  effected  by  the  rending  of 
a  delicate  forming  tissue.  And  if  some  of  this  apparant  mucilage  be 
scraped  off  from  the  surface  of  the  wood,  and  examined  under  a  good 
microscope,  it  will  be  seen  to  be  a  thin  stratum  of  young  wood-cells, 
with  the  ends  of  medullary  rays  here  and  there  interspersed,  and 
appearing  much  as  in  Fig.  193,  only  the  young  wood-cells  are  mostly 
shorter.  The  inner  portion  of  the  cambium-layer  is  therefore  nas- 
cent Avood,  and  the  outer  is  nascent  bark.  And  it  is  by  the  growth 
of  the  cambium-layer,  renewed  year  after  year,  that  the 

221.  Annual  Increase  Of  tllC  Wood  of  Exogenous  plants  is  effected. 
As  the  cells  of  this  layer  multiply,  the  greater  number  lengthen  ver- 
tically into  prosenchyma  or  woody  tissue  ;  while  some  are  trans- 
formed into  ducts,  and  others,  remaining  as  parenchyma,  continue  the 
medullary  rays  or  commence  new  ones.  In  this  way  a  second  layer 
of  wood  is  formed  the  second  season,  over  the  whole  surface  of  the 
former  layer  and  between  it  and  the  bark,  and  continuous  with  the 
woody  layer  of  the  new  roots  below  and  of  the  leafy  shoots  of  the 
season  above.  Each  succeeding  year  another  layer  is  added  to  the 
wood  in  the  same  manner,  coincident  with  the  growth  in  length  by 
the  development  of  the  buds.  A  cross-section  of  an  exogenous  stem, 
therefore,  exhibits  the  wood  disposed  in  concentric  rings  between 
the  bark  and  the  pith ;  the  oldest  lying  next  the  latter,  and  the 
youngest  occupying  the  circumference.  Each  layer  being  the  pro- 
duct of  a  single  year's  growth,  the  age  of  an  exogenous  tree  may,  in 
general,  be  correctly  ascertained  by  counting  the  rings  in  a  cross- 
section  of  the  trunk.* 


*  The  annual  layers  are  most  distinct  in  trees  of  temperate  climates  like  ours, 
where  there  is  a  prolonged  period  of  total  repose,  from  the  winter's  cold,  fol- 
lowed by  a  vigorous  resumption  of  vegetation  in  spring.  In  tropical  trees  they 
are  rarely  so  well  defined ;  but  even  in  these  there  is  generally  a  more  or  less 
marked  annual  suspension  of  vegetation,  occurring,  however,  in  the  dry  and 
hotter,  rather  than  in  the  cooler  season.  There  are  numerous  cases,  moreover, 
in  which  the  wood  forms  a  uniform  stratum,  whatever  be  the  age  of  the  trunk, 
as  in  the  arborescent  species  of  Cactus  ;  or  where  the  layers  are  few  and  by  no 
means  corresponding  with  the  age  of  the  trunk,  as  in  the  Cycas. 

In  many  woody  climbing  or  twining  stems,  such  as  those  of  Clematis,  Aristo- 


124  THE    STEM. 

222.  The  Limitation  of  the  Annual  Layers  results  from  two  or  more 

causes,  separate  or  combined.  In  oak  and  chestnut  wood,  and  the 
like,  the  layers  are  strongly  defined  by  reason  of  the  accumulation  of 
the  large  dotted  ducts,  here  of  extreme  size  and  in  great  abundance, 
in  the  inner  portion  of  each  layer,  where  their  open  mouths  on  the 
cross-section  are  conspicuous  to  the  naked  eye,  making  a  strong  con- 
trast between  the  inner  porous,  and  the  exterior  solid  part  of  the 
successive  layers.  In  Maple  and  Beech  wood,  however,  the  ducts 
are  smaller,  and  are  dispersed  throughout  the  whole  breadth  of  the 
layer ;  and  in  coniferous  wood,  viz.  that  of  Pine,  Cypress,  &c,  there 
are  no  ducts  at  all,  but  only  a  uniform  woody  tissue  of  a  peculiar 
sort  (46,  54).  Here  the  demarcation  between  two  layers  is  owing 
to  the  greater  fineness  of  the  wood-cells  formed  at  the  close  of  the 
season,  viz.  those  at  the  outer  border  of  the  layer,  while  the  next 
layer  begins,  in  its  vigorous  vernal  growth,  with  much  larger  cells, 
thus  marking  an  abrupt  transition  from  one  layer  to  the  next.  Be- 
sides being  finer,  the  last  wood-cells  of  the  season  are  often  flattened 
laterally,  more  or  less. 

223.  Each  layer  of  wood,  once  formed,  remains  unchanged  in  posi- 
tion and  dimensions.  But  in  trunks  of  considerable  age,  the  older 
layers  generally  undergo  more  or  less  change  in  color  and  density, 
distinguishing  the  Avood  into  two  parts,  viz. 

224.  Sap-WOOtl  and  Heart-WOOd.  In  the  germinating  plantlet  and  in 
the  developing  bud,  the  sap  ascends  through  the  whole  tissue,  of 
whatever  sort ;  at  first  through  the  parenchyma,  for  there  is  then  no 
other  tissue  ;  and  the  transmission  is  continued  through  it,  especially 
through  its  central  portion,  or  the  pith,  in  the  growing  apex  of  the 
stem  throughout.  But  in  the  older  parts  below,  the  pith,  soon 
drained  of  sap,  becomes  filled  with  air  in  its  place,  and  thenceforth  it 
bears  no  part  in  the  plant's  nourishment.  As  soon  as  wood-cells  and 
ducts  are  formed,  they  take  an  active  part  in  the  conveyance  of  sap ; 


lochia  Sipho,  and  Mcnispermum  Canadcnse,  the  annual  layers  are  rather  obscure- 
ly marked,  while  the  medullary  rays  are  unusually  broad ;  and  the  wood  therefore 
forms  a  series  of  separable  wedges  disposed  in  a  circle  around  the  pith.  In  the 
stem  of  one  of  our  Trumpet-creepers  (the  Bignonia  capreolata)  the  annual  rings, 
after  the  first  four  or  five,  are  interrupted  in  four  places,  and  here  as  many  broad 
plates  of  cellular  tissue,  belonging  properly  to  the  bark,  are  interposed,  passing 
at  right  angles  to  each  other  from  the  circumference  towards  the  centre,  so  that 
the  transverse  section  of  the  wood  nearly  resembles  a  Maltese  cross.  But  these 
are  all  exceptional  cases,  which  scarcely  require  notice  in  a  general  view. 


SAP-WOOD    AND    HEART-WOOD. 


125 


for  which  their  tubular  and  capillary  character  is  especially  adapted. 
But  the  ducts  in  older  parts,  except  when  gorged  with  sap,  contain 
air  alone  ;  and  in  woody  trunks  the  sap  continues  to  rise  year  after 
year,  to  the  places  where  growth  is  going  on,  mainly  through  the 
proper  woody  tissue  of  the  wood.  In  this  transmission  the  new  layers 
are  most  active,  and  these  are  in  direct  communication  with  the  new 
roots  on  the  one  hand  and  with  the  buds  or  shoots  and  leaves  of  the 
season  on  the  other.  So,  by  the  formation  of  new  annual  layers  out- 
side of  them,  the  older  ones  are  each  year  removed  a  step  farther 
from  the  region  of  growth;  or  rather  the  growing  stratum,  which 
connects  the  fresh  rootlets  that  imbibe  with  the  foliage  that  elabo- 
rates the  sap,  is  each  year  removed  farther  from  them.  The  latter, 
therefore,  after  a  few  years,  cease  to  convey  sap,  as  they  have  long 


FIG.  196.  Magnified  cross-section  of  a  portion  of  woody  tissue  of  White  Oak,  a  year  old. 
197.  A  longitudinal  as  well  as  cross  section  of  the  same,  a  little  higher  magnified,  a,  a,  Por- 
tions of  one  of  the  smaller  medullary  rays. 

FIG.  198.     Magnified  cross-section  of  woody  tissue  from  the  same  stem,  taken  from  a  layer 
of  heart-wood,  24  years  old:   6,  ducts  :  a,  portion  of  one  of  the  minuter  medullary  rays.     199. 
Combined  cross  and  longitudinal  section  of  the  same :  a,  tissue  of  a  medullary  ray. 
11* 


126  THE    STEM. 

before  ceased  to  take  part  in  any  vital  operations.  The  cells  of  the 
older  layers,  also,  commonly  have  thicker  walls  and  smaller  calibre 
than  those  of  the  newer,  —  as  here  shown  in  Fig.  198, 199,  compared 
with  Fig.  196,  197,  —  owing  to  the  greater  amount  of  thickening  or- 
ganic materials  (43)  mingled  with  encrusting  mineral  matters  intro- 
duced with  the  water  imbibed  by  the  roots  (93)  which  have  been  de- 
posited upon  them  from  within.  This  older,  more  solidified,  and  harder 
wood,  which  occupies  the  centre  of  the  trunk,  and  is  the  part  princi- 
pally valuable  for  timber,  &c,  is  called  Heart- wood,  or  Duramen  : 
while  the  newer  layers  of  softer,  more  open,  and  bibulous  wood,  more 
or  less  charged  with  sap,  receive  the  name  of  Sap-wood,  or  Albur- 
num. The  latter  name  was  given  by  the  earlier  physiologists  in  allu- 
sion to  its  white  or  pale  color.  In  all  trees  which  have  the  distinction 
between  the  sap-wood  and  heart-wood  well  marked,  the  latter  acquires 
a  deeper  color,  and  that  peculiar  to  the  species,  such  as  the  dark  brown 
of  the  Black  Walnut,  the  blacker  color  of  the  Ebony,  the  purplish-red 
of  Red  Cedar,  and  the  bright  yellow  of  the  Barberry.  These  colors 
are  owing  to  special  vegetable  products  mixed  with  the  incrusting 
matters  ;  but  sometimes  the  hue  appers  to  be  rather  an  alteration  of 
the  lignine  with  age.  In  the  Red  Cedar,  the  deep  color  belongs 
chiefly  to  the  medullary  rays.  In  many  of  the  softer  Avoods,  there  is 
little  thickening  of  the  cell-walls,  and  little  change  in  color  of  the 
heart-wood,  except  from  incipient  decay,  as  in  the  White  Pine,  Pop- 
lar, Tulip-tree,  &c.  The  heart-wood  is  no  longer  in  any  sense  a 
living  part ;  it  may  perish,  as  it  frequently  does,  without  affecting  the 
life  or  health  of  the  tree. 

225.  The  Bark  is  much  more  various  in  structure  and  growth  than 
the  wood :  it  is  also  subject  to  grave  alterations  with  advancing  age, 
on  account  of  its  external  position,  viz.  to  distention  from  the  con- 
stantly increasing  diameter  of  the  stem  within,  and  to  abrasion  and 
decay  from  the  influence  of  the  elements  without.  It  is  never  entire, 
therefore,  on  the  trunks  of  large  trees  ;  but  the  dead  exterior  parts, 
no  longer  able  to  enlarge  with  the  enlarging  Avood,  are  gradually 
fissured  and  torn,  and  crack  off  in  layers,  or  fall  away  by  slow  decay. 
So  that  the  bark  of  old  trunks  bears  but  a  small  proportion  in  thick- 
ness to  the  wood,  even  when  it  makes  an  equal  amount  of  annual 
growth. 

226.  The  three  parts  of  the  bark  (214-217),  for  the  most  part 
readily  distinguishable  in  the  bark  of  young  shoots,  grow  indepen- 
dently, each  by  the  addition  of  new  cells  to  its  inner  face,  so  long  as 


THE    BARK.  127 

it  grows  at  all.  The  green  layer  does  not  increase  at  all  after  the 
first  year  ;  the  opaque  corky  layer  soon  excludes  it  from  the  light ; 
and  it  gradually  perishes,  never  to  be  renewed.  The  corky  layer 
commonly  increases  for  a  few  years  only,  by  the  formation  of  new 
tabular  cells  :  occasionally  it  takes  a  remarkable  development,  form- 
ing the  substance  called  Cork,  as  in  the  Cork  Oak.  A  similar  growth 
occurs   on   the   bark   of   several 

species  of  Elm,  of  our    Liquid-        t____j  <g^  i^Z^^llS. gUfp 
amoai    01    oweei  v*uni,  occ.,  pro       b ^^^^^gg^^^@^@_ 
ducing  thick  corky  plates  on  the     °  §S§  ^§^i^§^ss£iEE%  §1§ 
branches.     In  the  White  and  Pa-     b    ®s eB®©fg»®®© sc-^h %. 
per  Lirai,  thin  layers,  of  a  very 
durable    nature,  are  formed   for 
a  great  number  of  years  ;    each 
layer  of  tabular  and  firmly  cohe- 
rent  cells  (I  lg.  200,  a)  alternates  (Sias^a^'SSi 

with  a  thinner  stratum  of  delicate,  200 

somewhat  cubical  and  less  compact  cells  (b),  which  break  up  into  a 
fine  powder  when  disturbed,  mad  allow  the  thin,  paper-like  plates  to 
exfoliate. 

227.  The  liber,  or  inner  bark  (215),  continues  to  grow  through- 
out the  life  of  the  tree,  by  an  annual  addition  from  the  cambium- 
layer  applied  to  its  inner  surface.  Sometimes  the  growth  is  plainly 
distinguishable  into  layers,  corresponding  with  or  more  numerous 
than  the  annual  layers  of  the  wood :  often,  there  is  scarcely  any 
trace  of  such  layers  to  be  discerned.  In  composition  and  appearance 
the  liber  varies  greatly  in  different  plants,*  especially  in  trees  and 
shrubs.  That  of  Bass-wood  or  Linden,  and  of  other  plants  with 
a  similar  fibrous  bark,  may  be  taken  as  best  representing  the  liber. 
Here  it  consists  of  strata  of  very  thick-walled  cells  alternating  with 
thin-walled  cells.  The  thick-walled  cells  are  bast-cells  (55,  Fig.  49, 
53),  are  much  elongated  vertically,  and  form  the  fibrous  portion  of 


*  The  best  account  of  the  liber  that  has  yet  been  given  is  that  by  Mohl, 
in  the  Botanische  Zeitung ,  Vol.  13,  p.  873  (1855),  of  which  a  French  translation  is 
published  in  the  Annates  des  Sciences  Naturelles,  ser.  4,  Vol.  5,  p.  141,  et  seq. 
(1856). 

FIG.  200.  Transverse  section  of  a  minute  portion  of  White  Birch  bark,  the  corky  layer 
highly  magnified  :  a,  the  firm,  tabular  cells,  b,  delicate  thin-walled  cells  which  separate  the 
papery  plates.     (After  Link.) 


128  the  stem:. 

the  bark.  The  thin-walled  cells  are  those  of  ordinary  parenchyma, 
mingled,  at  the  inner  part  of  each  stratum,  with  larger  and  longer 
ones,  marked  (on  some  sides  at  least)  with  the  thin  and  reticulated 
spots  or  punctuations  already  described  (215).  These  last  may  be 
termed  the  proper  cells  of  the  liber,  as  they  are  peculiar  to  this  part 
of  the  bark,  are  seldom  if  ever  absent,  they  contain  an  abundance  of 
mucilage  and  proteine,  and  in  all  probability  they  take  the  principal 
part  in  the  descending  circulation  of  the  plant,  if  it  may  so  be  called, 
i.  e.  in  conveying  downwards  and  distributing  the  rich  sap  which  has 
been  elaborated  in  the  foliage.  It  is  evident  that  the  bast-cells, 
which  in  Linden  (Fig.  53)  are  seen  to  be  almost  solid,  are  not 
adapted  to  this  purpose. 

228.  That  bast-cells  are  not  an  essential  part,  is  further  evident 
from  the  fact,  that  they  are  altogether  wanting  in  the  bark  of  some 
plants,  and  are  not  produced  after  the  first  year  in  many  others.  The 
latter  is  the  case  in  Negundo,  where  abundant  bast-cells,  like  those 
of  Bass-wood,  compose  the  exterior  portion  of  the  first  year's  liber 
(Fig.  194,  195,  b),  but  none  whatever  is  formed  in  the  subsequent 
layers.  In  Beeches  and  Birches,  also,  a  few  bast-cells  are  produced 
the  first  year,  but  none  afterwards.  In  Maples  a  few  are  formed  in 
succeeding  years.  In  the  Pear  bast-cells  are  annually  formed,  but 
in  very  small  quantity,  compared  with  the  parenchymatous  part  of 
the  liber.  In  Pines,  at  least  in  White  Pines,  the  bark  is  nearly  as 
homogeneous  as  the  wood,  the  whole  liber,  except  what  answers  to 
the  medullary  rays,  consisting  of  one  kind  of  cells,  resembling  those 

of  bast  or  of  wood  in  form,  but  agree- 
ing with  the  proper  liber-cells  in  their 
structure  and  markings.  Although 
the  liber  of  Birch  produces  no  bast- 
cells  after  the  first  year,  it  abounds 
in  short  cells  equally  solidified  by  in- 
ternal deposition,  and  of  a  gritty  tex- 
ture, which  might  be  mistaken  for 
201  bast-cells   on   the  cross-section   (Fig. 

201).     A  longitudinal  section  discloses  the  difference. 

229.  The  bark  on  old  stems  is  constantly  decaying  or  falling  away 
from  the  surface,  Avithout  any  injury  to  the  tree  ;  just  as  the  heart- 
wood  may  equally  decay  within  without  harm,  except  by  mechani- 

FIG.  201.  Cross-section  of  a  cluster  of  solidified  and  indurated  cells  from  the  liber  of  the 
White  Birch.    (After  Link.) 


THE    LIVING    PARTS    OF   A    TREE.  129 

cally  impairing  the  strength  of  the  trunk.  Great  differences  are 
observable  as  to  the  time  and  manner  in  which  the  older  bark 
of  different  shrubs  and  trees  is  thrown  off,  according  to  the  struc- 
ture in  each  species.  Some  trees  and  shrubs  have  their  trunks  in- 
vested with  the  liber  of  many  years'  growth,  although  only  the  in- 
nermost layers  are  alive ;  in  others  it  scales  off  much  earlier.  On 
the  stems  of  the  common  Honeysuckle,  of  the  Nine-Bark  (Spiraea 
opulifolia),  and  of  Grape-vines  (except  of  our  Muscadine  Grape), 
the  liber  lives  only  one  season,  and  is  detached  the  following  year, 
hanging  loose  in  papery  layers  in  the  former  species,  and  in  fibrous 
shreds  in  the  latter. 

230.  While  the  newer  layers  of  the  wood  abound  in  crude  sap, 
which  they  convey  to  the  leaves  (224),  those  of  the  inner  bark 
abound  in  elaborated  sap  (79,  227),  which  they  receive  from  the 
leaves  and  convey  to  the  cambium-layer  or  zone  of  growth.  The 
proper  juices  and  peculiar  products  of  plants  (88)  are  accordingly 
found  in  the  foliage  and  the  bark,  especially  in  the  latter.  In  the 
bark,  therefore,  (either  of  the  stem  or  of  the  root,)  medicinal  and 
other  principles  are  usually  to  be  sought,  rather  than  in  the  wood. 
Nevertheless,  as  the  wood  is  kept  in  connection  with  the  bark  by 
the  medullary  rays,  many  products  which  probably  originate  in  the 
former  are  deposited  in  the  wood. 

231.  The  living  Parts  of  a  Tree  or  Shrub,  of  the  Exogenous  kind,  are 
obviously  only  these:  —  1st.  The  summit  of  the  stem  and  branches, 
with  the  buds  which  continue  them  upwards  and  annually  develop 
the  foliage.  2d.  The  fresh  tips  of  the  roots  and  rootlets  annually 
developed  at  the  opposite  extremity.  3d.  The  newest  strata  of  wood 
and  bark,  and  especially  the  interposed  cambium-layer,  which,  annu- 
ally renewed,  maintain  a  living  communication  between  the  rootlets 
on  the  one  hand  and  the  buds  and  foliage  on  the  other,  however  dis- 
tant they  at  length  may  be.  These  are  all  that  is  concerned  in  the 
life  and  growth  of  the  tree  ;  and  these  are  annually  renewed.  The 
branches  of  each  year's  growth  are,  therefore,  kept  in  fresh  commu- 
nication, by  means  of  the  newer  layers  of  wood,  with  the  fresh 
rootlets,  which  are  alone  active  in  absorbing  the  crude  food  of  the 
plant  from  the  soil.  The  fluid  they  absorb  is  thus  conveyed  directly 
to  the  branches  of  the  season,  which  alone  develop  leaves  to  digest 
it.  And  the  sap  they  receive,  having  been  elaborated  and  converted 
into  organic  nourishing  matter,  is  partly  expended  in  the  upward 
growth  of  new  branches,  and  partly  in  the  formation  of  a  new  layer 


130  THE    STEM. 

of  wood,  reaching  from  the  highest  leaves  to  the  remotest  rootlets.* 
As  the  exogenous  tree,  therefore,  annually  renews  its  buds  and 

*  The  layers  of  wood  and  bark,  by  which  the  exogenous  stem  annually  in- 
creases in  diameter,  are  formed  by  the  multiplication  of  the  cells  of  the  cambium- 
layer  throughout  its  whole  extent.  That  the  organic  material  to  supply  this 
growth  in  ordinary  vegetation  descends  in  the  bark,  for  the  most  part,  and  that 
the  order  of  growth  in  the  formation  of  wood  is  from  above  downwards,  and 
also  the  general  dependence  of  this  growth  upon  the  action  of  the  foliage,  may 
be  inferred  from  a  variety  of  facts  and  considerations.  The  connection  of  the 
wood  with  the  leaves  is  shown: — (1.)  By  tracing  the  threads  of  soft  woody 
Endogens,  such  as  Yucca,  directly  from  the  base  of  the  leaf  into  the  stem,  and 
thence  downward  to  their  termination,  towards  which  they  become  attenuated, 
lose  their  vessels,  and  are  finally  reduced  to  slender  shreds  of  woody  tissue. 
(2.)  The  amount  of  wood  formed  in  a  stem  or  branch,  other  things  being  equal, 
is  in  a  relation  to  the  number  and  size  of  the  leaves  it  bears ;  its  amount  in  any 
portion  of  the  branch  is  in  direct  proportion  to  the  number  of  leaves  above  that 
portion.  Thus,  when  the  leaves  are  distributed  along  a  branch,  it  tapers  to  the 
6ummit,  as  in  a  common  Reed  or  a  stalk  of  Indian  Corn  ;  when  they  grow  in  a 
cluster  at  the  apex,  it  remains  cylindrical,  as  in  a  Palm  (Fig.  184).  Consequently 
the  increase  of  the  trunk  in  diameter  directly  corresponds  with  the  number  and 
vigor  of  the  branches.  The  greater  the  development  of  vigorous  branches  on  a 
particular  side  of  a  tree,  the  more  wood  is  formed,  and  the  greater  the  thickness 
of  the  annual  layers  on  that  side  of  the  trunk.  (3.)  In  a  seedling,  the  wood 
appears  in  proportion  as  the  leaves  are  developed.  (4.)  If  a  young  branch  be 
cut  off  just  below  a  node  (156),  so  as  to  leave  an  internode  without  leaves  or 
bud,  little  or  no  increase  in  diameter  will  ordinarily  take  place  down  to  the  first 
leaf  below.  But  if  a  bud  be  inserted  into  this  naked  internode,  as  the  bud  de- 
velops, increase  in  diameter,  with  the  formation  of  new  wood,  recommences. 
That  the  formation  proceeds  from  above  downwards,  or  that  the  elaborated  sap 
which  furnishes  the  material  for  the  growth  is  diffused  from  above  downwards, 
appears  from  the  effect  of  a  ligature  around  exogenous  stems,  or  of  removing  a 
ring  of  bark.  It  is  a  familiar  fact,  that,  when  a  ligature  is  closely  bound  around 
a  growing  exogenous  stem,  the  part  above  the  ligature  swells,  and  that  below 
docs  not.  Every  one  may  have  observed  the  distortions  that  twining  stems  thus 
accidentally  produce  upon  woody  exogenous  trunks,  causing  an  enlargement  on 
the  upper  side  of  the  obstruction.  When  the  stem  is  girdled,  by  removing  a 
ring  of  bark  so  as  completely  to  expose  the  surface  of  the  wood,  the  part  above 
the  ring  enlarges  in  the  same  manner ;  that  below  does  not,  until  the  incision  is 
healed.  The  wood  of  the  roots  is  manifestly  formed  in  a  descending  direction. 
But  this  is  continuous  with  that  of  the  stem;  and  its  first  layer,  the  extension  of 
the  wood  of  the  radicle  into  the  primary  root,  agrees  in  composition  with  the 
wood  of  the  succeeding  layers  in  the  stem,  having  no  spiral  vessels,  but  only 
ducts.  Still,  whatever  analogy  there  may  be  between  the  growth  of  the  wood 
in  the  stem  and  of  roots,  there  is  no  real  basis  for  the  ingenious  conception  of 
Thouars  and  of  Gaudichaud,  that  wood  is  the  roots  of  buds  or  leaves,  or  that 
it  is  absolutely  dependent  upon  them  for  its  formation. 


COMPOSITE    NATURE    OF   A   PLANT.  131 

leaves,  its  wood,  bark,  and  roots,  —  evei'ything,  indeed,  that  is  con- 
cerned in  its  life  and  groAvth,  —  there  seems  to  be  no  reason,  no 
necessary  cause  inherent  in  the  tree  itself,  why  it  may  not  live  in- 
definitely. Accordingly,  some  trees  are  known  to  have  lived  for 
twelve  hundred  years  or  more  ;  and  others  now  survive  which  are 
probably  above  two  thousand  years  old,  and  perhaps  much  older.* 
This  longevity  ceases  to  be  at  all  surprising  when  we  consider,  that, 
although  the  tree  or  herb  is  in  a  certain  sense  an  individual,  yet  it 
is  not  an  individual  in  the  sense  that  a  man  or  any  ordinary  animal 
is.     Viewed  philosophically, 

232.  The  Plant  is  a  Composite  Being,  or  community,  lasting,  in  the 
case  of  a  tree  especially,  through  an  indefinite  and  often  immense 
number  of  generations.  These  are  successively  produced,  enjoy  a 
term  of  existence,  and  perish  in  their  turn.  Life  passes  onward 
continually  from  the  older  to  the  newer  parts,  and  death  follows, 
with  equal  step,  at  a  narrow  interval.  No  portion  of  the  tree  is  now 
living  that  was  alive  a  few  years  ago ;  the  leaves  die  annually  and 
are  cast  off,  while  the  internodes  or  joints  of  stem  that  bore  them,  as 
to  their  wood  at  least,  buried  deep  in  the  trunk,  under  the  wood 
of  succeeding  generations,  are  converted  into  lifeless  heart-wood,  or 
perchance  decayed,  while  the  bark  that  belonged  to  them  is  thrown 
off  from  the  surface.  It  is  the  aggregate,  the  blended  mass  alone, 
that  long  survives.  Plants  of  single  cells,  and  of  a  definite  form, 
alone  exhibit  complete  individuality ;  and  their  existence  is  ex- 
tremely brief.  The  more  complex  vegetable  of  a  higher  grade  is 
not  to  be  compared  with  the  animal  of  the  highest  organization, 
where  the  offspring  always  separates  from  the  parent,  and  the  indi- 
vidual is  simple  and  indivisible.  But  it  is  truly  similar  to  the  branch- 
ing or  arborescent  coral,  or  to  other  compound  animals  of  the  lowest 
grade,  where  successive  generations,  though  capable  of  living  inde- 
pendently and  sometimes  separating  spontaneously,  yet  are  usually 
developed  in  connection,  blended  in  a  general  body,  and  nourished 
more  or  less  in  common.  Thus  the  coral  structure  is  built  up  by 
the  combined  labors  of  a  vast  number  of  individuals,  —  by  the  suc- 


*  The  subject  of  the  longevity  of  trees  has  been  ably  discussed  by  De  Can- 
dolle,  in  the  Bibliotheque  Universelle  of  Geneva,  for  May,  1831,  and  in  the  second 
volume  of  his  Plujsiologie  Vegetale  :  also,  more  recently,  by  Professor  Alphonso 
De  Candollc.  In  this  country,  an  article  on  the  subject  has  appeared  in  the 
North  American  Review,  for  July,  1 844. 


132  THE    STEM. 

cesslve  labors  of  a  great  number  of  generations.  The  surface  or  the 
recent  shoots  alone  are  alive  ;  and  here  life  is  superficial,  all  under- 
neath consisting  of  the  dead  remains  of  former  generations.  The 
arborescent  species  are  not  only  lifeless  along  the  central  axis,  but 
are  dead  throughout  towards  the  bottom  :  as,  in  a  genealogical  tree, 
only  the  later  ramifications  are  among  the  living.  It  is  the  same 
with  the  vegetable,  except  that,  as  it  ordinarily  imbibes  its  nourish- 
ment mainly  from  the  soil  through  its  roots,  it  makes  a  downward 
growth  also,  and,  by  constant  renewal  of  fresh  tissues,  maintains  the 
communication  between  the  two  growing  extremities,  the  buds  and 
the  rootlets. 

233.  Individuality  being  imperfectly  realized  in  the  vegetable 
kingdom,  the  question  as  to  what  in  the  Phamogamous  plant  best 
answers  to  the  animal  individual  is  speculative,  rather  than  practical, 
and  may  be  more  appropi'iately  noticed  in  another  place.  (Part  II. 
Chap.  I.) 

234.  Comparison  of  Endogenous  with  Exogenous  Structure.    The  woody 

bundles  of  an  exogenous  stem  (Fig.  186-188)  continue  to  grow  on 
the  outer  side  as  long  as  the  plant  lives.  In  woody  trunks  they  at 
once  become  wedges  with  the  point  next  the  pith,  and  growth  pro- 
ceeds indefinitely  by  the  stratum  of  perpetually  renewed  tissue  on 
the  outer  face  between  the  wood  and  the  bark.  Each  wedge  is 
separated  from  its  neighbor  on  both  sides  by  an  interposed  medul- 
lary ray,  and  is  composed  of  wood  on  the  inner  side,  liber  on  the 
outer,  and  cambium  or  forming  tissue  between.  Now  each  thread 
or  bundle  of  endogenous  wood  (204)  is  composed  of  similar  or  anal- 
ogous parts,  sometimes  irregularly  intermixed,  but  more  commonly 
similarly  disposed.  That  is,  the  section  of  one  of  these  threads  ex- 
hibits woody  tissue  and  one  or  two  spiral  vessels  on  its  inner  border, 
answering  to  the  proper  wood,  and  very  thick-walled  elongated  cells 
on  its  outer  border,  of  the  same  nature  as  the  bast-cells  of  Exogens ; 
and  between  the  two  is  a  stratum  of  cells  of  parenchyma  mixed  with 
elongated  and  punctuated  cells  answering  to  the  proper  cells  of  the 
inner  part  of  the  liber.  The  portion  of  each  endogenous  thread, 
therefore,  which  looks  towards  the  centre  of  the  trunk,  answers  to 
the  wood,  and  its  outer  portion  to  the  liber  or  inner  bark,  of  the  ex- 
ogenous stem ;  and  the  parenchyma  through  which  the  threads  are 
interspersed  answers  to  the  medullary  rays  and  pith  together.  The 
main  difference  between  the  endogenous  woody  threads  and  the  ex- 
ogenous woody  wedges  is,  that  there  is  no  cambium-layer  in  the 


THE    LEAVES.  133 

former  between  the  liber  and  the  wood,  and  therefore  no  provision 
for  increase  in  diameter.  The  bundles  are  therefore  strictly  limited, 
while  tbose  of  Exogens  are  unlimited  in  growth.  In  Exogens  the 
woody  bundles  or  wedges,  symmetrically  arranged  in  a  circle,  be- 
come confluent  into  a  zone  in  all  woody  and  most  herbaceous  stems, 
which  continues  to  increase  in  thickness.  In  Endogens  the  woody 
bundles  are  unchanged  in  size  after  their  formation,  but  new  and 
distinct  ones  are  formed  in  the  growing  stem  with  each  leaf  it  de- 
velops, and  interspersed  more  or  less  irregularly  among  the  older 
bundles. 


CHAPTER     V. 

OF   THE   LEAVES. 
Sect.  I.     TriEiR  Arrangement.     (Phyllotaxis,  etc.) 

235.  TriE  situation  of  leaves,  as  well  as  their  general  office  in  the 
vegetable  economy,  and  several  of  their  special  adaptations,  has 
already  been  stated.  Leaves  invariably  arise  from  the  nodes  (156), 
just  below  the  point  where  buds  appear.  So  that  wherever  a  bud 
or  branch  is  found,  a  leaf  exists,  or  has  existed,  either  in  a  perfect  or 
rudimentary  state,  just  beneath  it ;  and  buds  (and  therefore  branch- 
es), on  the  other  hand,  are  or  may  be  developed  in  the  axils  of  all 
leaves,  and  do  not  normally  exist  in  any  other  situation.  The  point 
of  attachment  of  a  leaf  (or  other  organ)  with  the  stem  is  termed  its 
insertion.  The  subject  of  the  arrangement  of  leaves  on  the  stem  has 
received  the  name  of 

236.  Phyllotaxis  (from  two  Greek  words,  signifying  leaf-arrange- 
ment). 

237.  As  to  their  general  position,  leaves  are  either  alternate,  oppo- 
site, or  verticillate.  They  are  said  to  be  alternate  (127,  and  Fig. 
121,  157,  204)  when  there  is  only  one  to  each  node,  in  which 
case  the  successive  leaves  are  thrown  alternately  to  different  sides 
of  the  stem.  They  are  said  to  be  opposite  when  each  node  bears 
a  pair  of  leaves,  in  which  case  the  two  leaves  always  diverge 
from  each  other  as  widely  as  possible,  that  is,  they  stand  on  opposite 

12 


134 


THE     LEAVES. 


sides  of  the  stem  and  point  in  opposite  directions  (127,  Fig.  107, 
210,  &c).  They  are  verticillate,  or  wJwrled,  when  there  are  three  or 
more  leaves  in  a  circle  (verticil  or  whorl)  upon  each  node  ;  in  which 
case  the  several  leaves  of  the  circle  diverge  from  each  other  as  much 
as  possible,  or  are  equably  distributed  around  the  whole  circumfer- 
ence of  the  axis  (Fig.  134,  211).  The  first  of  the  three  is  the 
simplest  as  well  as  the  commonest  method,  occurring  as  it  does  in 
almost  every  Monocotyledonous  plant  (where  it  is  plainly  the  normal 
mode,  128),  and  in  the  larger  number  of  Dicotyledonous  plants 
likewise,  after  the  first  or  second  nodes  (Fig.  Ill*,  121).  It 
should  therefore  be  first  examined. 

20O  238.  Alternate  leaves.      This  general  term 

for  the  case  where  leaves  are  placed  one  after 
another,  obviously  comprises  a  variety  of 
modes  as  to  the  particular  position  of  succes- 
sive leaA'es.  There  is,  first,  the  case  to  which 
the  name  is  most  applicable,  viz.  where  the 
leaves  are  alternately  disposed  on  exactly  op- 
posite sides  of  the  stem  (as  in  Fig.  157)  ;  the 
second  leaf  being  on  the  side  farthest  from  the 
first,  while  the  third  is  equally  distant  from 
the  second,  and  is  consequently  placed  directly 
over  the  first,  the  fourth  stands  over  the 
second,  and  so  on  throughout.  Such  leaves 
are  accordingly  distichous  or  two-ranked,* 
They  form  two  vertical  rows :  on  one  side 
are  the  1st,  3d,  5th,  7th,  &c. ;  on  the  op- 
posite side  are  the  2d,  4th,  6th,  8th,  and  so 
on.  This  mode  occurs  in  all  Grasses,  in  many 
other  Monocotyledonous  plants,  and  among 
the  Dicotyledonous  in  the  Linden.  A  second 
mode  is 

239.  The   tristichous   or    three-ranked  ar- 
rangement,  which  is  seen   in    Sedges   (Fig. 


*  In  the  course  of  the  summer  the  leaves  of  Baptisia  perfoliata,  which  are 
really  five-ranked,  often  appear  to  be  monostichous,  or  one-ranked;  but  this  is 
owing  to  a  torsion  of  the  axis. 

FIG.  202.  Tiece  of  a  stalk,  with  the  sheathing  bases  of  the  leaves,  of  a  Sedge-Grass  (Carex 
Crus-corvi),  showing  the  three-ranked  arrangement.  203.  Diagram  of  the  cross-section  of  the 
same,  showing  two  cycles  of  leaves. 


THEIR   ARRANGEMENT.  135 

202)  and  some  other  Monocotyledonous  plants.  Taking  any  leaf  we 
please  to  begin  with,  and  numbering  it  1,  we  pass  round  one  third  of 
the  circumference  of  the  stem  as  we  ascend  to  leaf  No.  2  ;  another 
third  of  the  circumference  brings  us  to  No.  3  ;  another  brings  us 
round  to  a  point  exactly  over  No  1,  and  here  No.  4  is  placed.  No.  5 
is  in  like  manner  over  No.  2,  and  so  on.  They  stand,  therefore,  in 
three  vertical  rows,  one  of  which  contains  the  numbers  1,  4,  7,  10 ; 
another,  2,  5,  8,  11  ;  the  third,  3,  6,  9,  12,  and  so  on.  If  we  draw  a 
line  from  the  insertion  of  one  leaf  to  that  of  the  next,  and  so  on  to 
the  third,  fourth,  and  the  rest  in  succession,  it  will  be  perceived  that 
it  winds  around  the  stem  spirally  as  it  ascends.  In  the  first  or  dis- 
tichous mode,  the  second  leaf  is  separated  from  the  preceding  by  half 
the  circumference  of  the  stem ;  and,  having  completed  one  turn 
round  the  stem,  the  third  begins  a  second  turn.  In  the  tristichous, 
each  leaf  is  separated  from  the  preceding  and  succeeding  by  one 
third  of  the  circumference,  there  are  three  leaves  in  one  turn,  or 
cycle,  and  the  fourth  commences  a  second  cycle,  which  goes  on  in 
the  same  way.  That  is,  the  angular  divergence,  or  arc  interposed 
between  the  insertion  of  two  successive  leaves,  in  the  first  is  J,  in  the 
second  •£,  of  the  circle.  These  fractions  severally  represent,  not 
only  the  angle  of  divergence,  but  the  whole  plan  of  these  two  modes ; 
the  numerator  denoting  the  number  of  times  the  spiral  line  winds 
round  the  stem  before  it  brings  a  leaf  directly  over  the  one  it  began 
with ;  while  the  denominator  expresses  the  number  of  leaves  that 
are  laid  down  in  this  course,  or  which  form  each  cycle.  The  two- 
ranked  mode  (J-)  is  evidently  the  simplest  possible  case.  The  tlu-ee- 
ranked  (J)  is  the  next,  and  the  one  in  which  the  spiral  character  of 
the  arrangement  begins  to  be  evident.     To  this  succeeds 

240.  The  pentastichous,  quincuncial,  or  Jive-ranked  arrangement 
(Fig.  204,  205).  This  is  much  the  most  common  case  in  alternate- 
leaved  Dicotyledonous  plants.  'The  Apple,  Cherry,  and  Poplar 
afford  ready  examples  of  it.  Here  there  are  five  leaves  in  each 
cycle,  since  Ave  must  pass  on  to  the  sixth  before  we  find  one  placed 
vertically  over  the  first.  To  reach  this,  the  ascending  spiral  line  has 
made  two  revolutions  round  the  stem,  and  on  it  the  five  leaves  are 
equably  distributed,  at  intervals  of  f  of  the  circumference.  The 
fraction  §  accordingly  expresses  the  angular  divergence  of  the  suc- 
cessive leaves  ;  the  numerator  indicates  the  number  of  turns  made 
in  completing  the  cycle,  and  the  denominator  gives  the  number  of 
leaves  in  the  cycle,  or  the  number  of  vertical  ranks  of  leaves  on  such 


136 


THE    LEAVES. 


a  stem.     If  we  shorten  the  axis,  as  it  was  in  the  hud,  or  make  a 
204  horizontal   plan,   we   have 

the  parts  disposed  as  in  the 
diagram,  Fig.  206,  the  low- 
er leaves  heing  of  course 
the  exterior. 

241.  The  eight-ranked 
arrangement,  the  next  in 
order,  is  likewise  not  un- 
common. It  is  found  in 
the  Holly,  the  Callistemon 
of  our  conservatories,  the 
Aconite,  the  tuft  of  leaves 
at  the  base  of  the  common 
Plantain,  &c.  In  this  case  the  ninth  leaf  is 
placed  over  the  first,  the  tenth  over  the  second, 
and  so  on ;  and  the  spiral  line  makes  three  turns 
in  laying  down  the  cycle  of  eight  leaves,  each 
separated  from  the  preceding  by  an  arc,  or  an- 
gular divergence,  of  f  of  the  circumference. 

242.  All  these  modes,  or  nearly  all  of  them,  206 

were  pointed  out  by  Bonnet  as  long  ago  as  the  middle  of  the  last 
century  ;  but  they  have  recently  been  extended  and  generalized,  and 
the  mutual  relations  of  the  various  methods  brought  to  light,  by 
Schimper,  Braun,  and  others.  If  we  write  down  in  order  the  series 
of  fractions  which  represent  the  simpler  forms  of  phyllotaxis  already 
noticed,  as  determined  by  observation,  viz.  £,  -1,  § ,  § ,  we  can  hardly 
fail  to  perceive  the  relation  that  they  bear  to  each  other.  For  the 
numerator  of  each  is  composed  of  the  sum  of  the  numerators  of  the 
two  preceding  fractions,  and  the  denominator  of  the  sum  of  the 
two  preceding  denominators.  Also  the  numerator  of  each  fraction  is 
the  denominator  of  the  next  but  one  preceding.  Extending  this 
series,  we  obtain  the  further  terms,  T5g-,  ?8T,  ^f ,  §  i,  &c.  Now  these 
numbers  are  verified  by  observation,  and,  with  some  abnormal  excep- 
tions, this  series  A,  1,  §,  •§,  T5ffJ  ?8T,  i|,  f  1  comprises  all  the  varia- 

FIG.  204.    A  branch  exhibiting  the  five-ranked  arrangement  of  leaves. 

FIG.  205.  Diagram  of  the  same  :  a  spiral  line  is  drawn  ascending  the  stem  and  passing 
through  the  successive  scars  which  mark  the  position  of  the  leaves  from  1  to  G.  It  is  made  a 
dotted  line  where  it  passes  on  the  opposite  side  of  the  stem,  and  the  scars  2  and  5,  which  fall 
on  that  side,  are  made  fainter.  206.  A  plane,  horizontal  projection  of  the  same  ;  the  dotted 
line  passing  from  the  edge  of  the  first  leaf  to  the  second,  and  so  on  to  the  fifth  leaf,  which 
completes  the  cycle  ;  as  the  sixth  would  come  directly  before,  or  within,  the  first. 


THEIR   ARRANGEMENT.  137 

tions  of  the-  arrangement  of  alternate  leaves  that  actually  occur. 
These  higher  forms  are  the  most  common  Avhere  the  leaves  are 
crowded  on  the  stem,  as  in  the  rosettes  of  the  Houseleek  (Fig.  207), 
and  the  scales  of  the  Pine-cones  (for  the  ar- 
rangement extends  to  all  parts  that  are  modifi- 
cations of  leaves),  or  where  they  are  numerous 
and  small  in  proportion  to  the  circumference  of 
the  stem,  as  the  leaves  of  Firs,  &c.  In  fact, 
when  the  internodes  are  long  and  the  base  of 
the  leaves  large  in  proportion  to  the  size  of  the 
stem,  it  is  difficult,  and  often  impossible,  to  tell 
whether  the  9th,  14th,  or  22d  leaf  stands  ex- 
actly over  the  first.  And  when  the  internodes  are  very  short,  so 
that  the  leaves  touch  one  another,  or  nearly  so,  we  may  readily  per- 
ceive what  leaves  are  superposed ;  but  it  is  then  difficult  to  follow 
the  succession  of  the  intermediate  leaves.  The  order,  however,  may 
be  deduced  by  simple  processes. 

243.  Sometimes  we  can  readily  count  the  number  of  vertical 
ranks,  which  gives  the  denominator  of  the  fraction  sought.  Thus,  if 
there  are  eight,  Ave  refer  the  case  to  the  f  arrangement  in  the  regu- 
lar series  ;  if  there  are  thirteen,  to  the  -jAj  arrangement,  and  so  on. 
Commonly,  however,  when  the  leaves  are  crowded,  the  vertical  ranks 
are  by  no  means  so  manifest  as  two  or  more  orders  of  oblique  series, 
or  secondary  spirals,  which  are  at  once  seen  to  wind  round  the 
axis  in  opposite  directions,  as  in  the  Houseleek  (Fig.  207  ;  where 
the  number's,  1,  6,  11  belong  to  a  spire  that  winds  to  the  left;  1, 
9,  17  to  another,  which  winds  to  the  right;  and  3,  G,  9,  12  to  still 
another,  that  winds  in  the  same  direction)  :  they  are  still  more  ob- 
vious in  Pine-cones  (Fig.  208,  209).  These  oblique  spiral  ranks 
are  a  necessary  consequence  of  the  regular  ascending  arrangement 
of  parts  with  equal  intervals  over  the  circumference  of  the  axis  :  and 
if  the  leaves  are  numbered  consecutively,  these  numbers  will  neces- 
sarily stand  in  arithmetical  progression  on  the  oblique  ranks,  and 
have  certain  obvious  relations  with  the  primary  spiral  which  origi- 
nates them  ;  as  will  be  seen  by  projecting  them  on  a  vertical  plane. 

244.  Take,  for  example,  the  quincunical  (f )  arrangement,  where, 
as  in  the  annexed  diagram,  the  ascending  spiral,  as  written  on  a 
plane  surface,  appears  in  the  numbers  1,  2,  3,  4,  5,  6,  and  so  on: 

FIG.  207.    An  offset  of  the  Houseleek,  with  the  rosette  of  leaves  unexpanded,  exhibiting  the 
5-13  arrangement ;  the  fourteenth  leaf  beiDg  directly  over  the  first. 

12* 


138 


THE    LKAVES. 


the  vertical  ranks  thus  formed,  beginning  with  the  lowest  (which 
we  place  in  the  middle  column,  that  it 
may  correspond  with  the  Larch-cone,  Fig. 
208,  where  the  lowest  scale,  1,  is  turned 
directly  towards  the  observer),  are  neces- 
sarily the  numbers  1,  6,  11  ;  4,  9,  14  ;  2,  7, 
12  ;  5,  10,  15  ;  and  3,  8,  13.  But  two 
parallel  oblique  ranks  are  equally  apparent, 
ascending  to  the  left ;  viz.  1,  3,  5,  which,  if  we  coil  the  diagram 
round  a  cylinder,  will  be  continued  into  7,  9,  11,  13,  15  ;  and  also 
2,  4,  G,  8, 10,  which  runs  into  12, 14,  and  so  on,  if  the  axis  be  further 
prolonged.  Here  the  circumference  is  occupied  by  two  secondary 
left-hand  series,  and  Ave  notice  that  the  common  difference  in  the 
sequence  of  numbers  is  two :  that  is,  the  number  of  the  parallel  sec- 
ondary spirals  is  the  same  as  the  common  difference  of  the  numbers 
on  the  leaves  that  compose  them.  Again,  there  are  other  parallel 
secondary  spiral  ranks,  three  in  number,  which  ascend  to  the  right ; 
viz.  1,  4,  7,  continued  into  10,  13  ;  3,  6,  9,  12,  continued  into  15  ; 
and  5,  8,  11,  14,  &c. ;  where  again  the  common  difference,  3,  accords 
with  the  number  of  such  ranks.  This  fixed  relation  enables  us  to 
lay  down  the  proper  numbers  on  the  leaves,  when  too  crowded  for 
directly  following  their  succession,  and  thus  to  ascertain  the  order  of 
the  primary  spiral  series  by  noticing  what  numbers  come  to  be  super- 
posed in  the  vertical  ranks.  AVe  take,  for  example,  the  very  simple 
cone  of  the  small-fruited  American  Larch  (Fig.  208),  which  usually 
completes  only  two  cycles  ;  for  we  see  that  the  lowest,  one  interme- 
diate, and  the  highest  scale,  on  the  side  towards  the  observer,  stand 
in  a  vertical  row.  Marking  this  lowest  scale  1,  and  counting  the 
parallel  secondary  spirals  that  wind  to  the  left,  we  find  that  two 
occupy  the  whole  circumference.  From  1,  we  number  on  the  scales 
of  that  spiral  3,  5,  7,  and  so  on,  adding  the  common  difference  2,  at 
each  step.  Again,  counting  from  the  base  the  right-hand  secondary 
spirals,  we  find  three  of  them,  and  therefore  proceed  to  number  the 
lowest  one  by  adding  this  common  difference,  viz.  1,4,7, 10;  then,  pass- 
ing to  the  next,  on  which  the  No.  3  has  already  been  fixed,  we  carry 
on  that  sequence,  6,  9,  &c. ;  and  on  the  third,  Avhere  No.  5  is  already 
fixed,  Ave  continue  the  numbering,  8,  11,  &c.  This  gives  us,  in  the 
A'ertical  rank  to  which  No.  1  belongs,  the  sequence  1,  6,  11,  shoAving 


FIG.  208.     A  cone  of  the  small-fruited  American  Larch  (Larix  Americana),  with  the  scales 
numbered,  exhibiting  the  five-ranked  arrangement,  as  in  the  annexed  diagram. 


THEIR   ARRANGEMENT. 


139 


that  the  arrangement  is  of  the  quincuncial  (f )  order.  It  is  further 
noticeable,  that  the  smaller  number  of  parallel  secondary  spirals,  2, 
agrees  with  the  numerator  of  the  fraction  in  this  the  §  arrangement ; 
and  that  this  number  added  to  that  of  the  parallel  secondary  spirals 
which  wind  in  the  opposite  direction,  viz.  3,  gives  the  denominator 
of  the  fraction.  This  holds  good  throughout ;  so  that  we  have  only 
to  count  the  number  of  parallel  secondary  spirals  in  the  two  direc- 
tions, and  assume  the  smaller  number  as  the  numerator,  and  the  sum 

Vertical   Projection  Vertical  Projection  of  the  -^ 

of  the  -|  Arrange-  Arrangement, 

ment.  27 

26 


2.3 


21 


23 


22 


19 


21 


20 


IS 


16 


11 


13 


12 


11 


2.:, 


24 


28 


22 


21 


20 


19 


IS 


17 


16 


IS 


14 


10 


± 

of  this  and  the  larger  number  as  the  denominator,  of  the  fraction 
which  expresses  the  angular  divergence  sought.     For  this  we  must 

FIG  209.  A  cone  of  the  White  Pine,  on  which  the  numbers  are  laid  down,  and  the  leading 
higher  secondary  spirals  are  indicated :  those  with  the  common  difference  8  are  marked  by 
dotted  lines  ascending  to  the  right ;  two  of  the  five  that  wind  in  the  opposite  direction  are 
also  marked  with  dotted  lines  :  the  set  with  the  common  difference  3,  in  one  direction,  and 
that  with  the  common  difference  2,  in  the  other,  are  very  manifest  in  the  cone. 


140  THE     LEAVES. 

take,  however,  the  order  of  secondary  spirals  nearest  the  vertical 
rank  in  each  direction,  when  there  are  more  than  two,  as  there  are 
in  all  the  succeeding  cases. 

245.  A  similar  diagram  of  the  f  arrangement  introduces  a  set  of 
secondary  spirals,  in  addition  to  the  two  foregoing,  ascending  in  a  near- 
er approach  to  a  vertical  line,  and  with  a  higher  common  difference, 
viz.  5.  There  are  accordingly  five  of  this  sort,  viz.  those  indicated 
in  the  diagram  by  the  series  1,  6,  11,  16  ;  4,  9,  14,  19,  24  ;  2,  7,  12, 
17,  22  ;  5, 10, 15,  20,  25  ;  and  3,  8, 13, 18,  23.  The  highest  obvious 
spiral  in  the  opposite  direction,  viz.  that  of  which  the  series  1,  4,  7, 
10,  13  is  a  specimen,  has  the  common  difference  3,  and  gives  the 
numerator,  and  3  -\-  5  the  denominator,  of  the  fraction  f .  The  next 
case,  T53,  which  is  exemplified  in  the  rosettes  of  the  Houseleek  (Fig. 
207)  and  in  the  cone  of  the  White  Pine  (Fig.  209),  introduces  a 
fourth  set  of  secondary  spirals,  eight  in  number,  with  the  common 
difference  eight,  viz.  that  of  which  the  series  1,  9,  17,  25  is  a  repre- 
sentative. The  set  that  answers  to  this  in  the  opposite  direction, 
viz.  1,  6,  11,  16,  21,  26,  with  the  common  difference  5,  gives  the 
numerator,  and  5  -J-  8  the  denominator,  of  the  fraction  T5^.  We  may 
here  compare  the  diagram  with  an  actual  example  (Fig.  209)  :  a 
part  of  the  numbers  are  of  course  out  of  sight  on  the  other  side  of 
the  cone.     The  same  laws  equally  apply  to  the  still  higher  modes. 

246.  The  order  is  uniform  in  the  same  species,  but  often  various 
in  allied  species.  Thus,  it  is  only  §  in  our  common  American  Larch ; 
in  the  European  species,  ^T.  The  White  Pine  is  -f^,  as  is  also  the 
Black  Spruce  ;  but  other  Pines  with  thicker  cones  exhibit  in  differ- 
ent species  the  fractions  ^8T,  -££ ,  and  f|.  Sometimes  the  primitive 
spiral  ascends  from  left  to  right,  sometimes  from  right  to  left.  One 
direction  or  the  other  generally  prevails  in  each  species,  yet  both 
directions  are  not  unfrequently  met  with,  even  in  different  cones  of 
the  same  tree. 

247.  When  a  branch  springs  from  a  stem  or  parent  axis,  the  spi- 
ral is  continued  from  the  leaves  of  the  stem  to  those  of  the  branch,  so 
that  the  leaf  from  Avhose  axil  the  branch  arises  begins  the  spire 
of  that  branch.  When  the  spire  of  the  branch  turns  in  the  same 
direction  as  that  of  the  parent  axis,  as  it  more  commonly  does,  it  is 
said  to  be  homodromous  (from  two  Greek  words,  signifying  like 
course)  :  when  it  turns  in  the  opposite  direction,  it  is  said  to  be 
heterodromous  (or  of  different  course). 

248.  The  cases  represented  by  the  fractions  £,  ■£,  and  §  are  the 


THEIK   ARRANGEMENT, 


141 


most  stable  and  certain,  as  well  as  the  easiest  to  observe.  In  the 
higher  forms,  the  exact  order  of  superposition  often  becomes  uncer- 
tain, owing  to  a  slight  torsion  of  the  axis,  or  to  the  difficulty  of 
observing  whether  the  9th,  14th,  22d,  35th,  or  56th  leaf  is  truly 
over  the  first,  or  a  little  to  the  one  side  or  the  other  of  the  vertical 
line.  Indeed,  if  we  express  the  angle  of  divergence  in  degrees  and 
minutes,  we  perceive  that  the  difference  is  so  small  a  part  of  the 
circumference,  that  a  very  slight  change  will  substitute  one  order  for 
another.  The  divergence  in  T57  =  138°  24'.  In  all  those  beyond, 
it  is  137°  plus  a  variable  number  of  minutes,  which  approaches 
nearer  and  nearer  to  30'.  Hence  M.  Bravais  considers  all  these  as 
mere  alterations  of  one  typical  arrangement,  namely,  with  the  angle 
of  divergence  137°  30'  28",  which  is  irrational  to  the  circumference, 
that  is,  not  capable  of  dividing  it  an  exact  number  of  times,  and  con- 
sequently never  bringing  any  leaf  precisely  in  a  right  line  over  any 
preceding  leaf,  but  placing  the  leaves  of  what  Ave  take  for  vertical 
ranks  alternately  on  both  sides  of  this  line  and  very  near  it,  approach- 
ing it  more  and  more,  without  ever  exactly  reaching  it.  These 
forms  of  arrangement  he  therefore  distinguishes  as  curvt'sen'al,  be- 
cause the  leaves  are  thus  disposed  on  an  infinite  curve,  and  are 
never  brought  into  exactly  straight  ranks.  The 
others  are  correspondingly  termed  rectiserial, 
because,  as  the  divergence  is  an  integral  part 
of  the  circumference,  the  leaves  are  necessarily 
brought  into  rectilineal  ranks  for  the  whole 
length  of  the  stem. 

249.  A  different  series  of  spirals  sometimes 
occurs  in  alternate  leaves,  viz.  £,  \,  f ,  T3f ;  and 
still  others  have  been  detected;  but  these  are 
rare  or  exceptional  cases. 

250.  Opposite  Leaves  (237,  Fig.  210).     In 

these,  almost  without  exception,  the  second  pair 

is  placed  over  the  intervals  of  the  first,  the  third 

over  the  intervals  of  the  second,  and  so  on. 

More  commonly,  as  in  plants  of  the   Labiate 

or  Mint  Family,  the  successive  pairs  cross  each 

other  exactly  at  right  angles,  so  that  the  third 

pair  stands  directly  over  the  first,  the  fourth  210 

over  the  second,  &c,  forming  four  equidistant  vertical  ranks  for  the 

FIG.  210.     Opposite  leaves  of  the  Strawberry-bush,  or  Euonymus  Americanus. 


142 


THE    LEAVES. 


whole  length  of  the  stem.  In  this  case,  the  leaves  are  said  to  he 
decussate.  In  other  cases,  as  in  the  Pink  Family,  often  the  succes- 
sive pairs  deviate  a  little  from  this  line,  so 
that  we  have  to  pass  several  pairs  before  we 
reach  one  exactly  superposed  over  the  pair 
we  start  with.  This  indicates  a  spiral  ar- 
rangement, which  falls  into  some  one  of  the 
modes  already  illustrated  in  alternate  leaves* 
only  that  here  each  node  bears  a  pair  of 
leaves. 
251.  Verticillate  or  Whorled  leaves  (Fig.  211) 

follow  the  same  modes  of  arrangement  as  op- 
posite leaves.     Sometimes  they  decussate,  or  the  leaves  of  one  whorl 
correspond  to  the  intervals   of  that  underneath,  making  twice  as 
many  vertical  ranks  as  there  are  leaves  in  the  whorl ; 
sometimes  they  wind  spirally,  so  that  each  leaf  of  the 
whorl  belongs  to  as  many  parallel  spirals,  analogous 
to   the    secondary    spirals    in   the    case   of  alternate 
leaves. 

252.  The  opposition  or  alternation  of  the  leaves  is 
generally  constant  in  the  same  species,  and  often 
through  the  same  family ;  yet  both  modes  occasionally 
occur  on  the  same  stem,  as  in  the  common  Snap- 
dragon and  the  Myrtle.  All  Exogens,  having  their 
cotyledons  opposite,  necessarily  commence  with  that 
mode  (Fig.  103-125);  many  retain  it  throughout ; 
others  change  to  alternation,  either  directly  in  the 
primordial  leaves  (Fig.  111°,  121),  or  at  a  later 
period.  In  Endogens,  on  the  contrary,  the  first  leaves 
are  necessarily  alternate  (128),  and  it  is  seldom  that 
they  afterwards  exhibit  opposite  or  whorled  leaves. 
The  Pine  in  germination  commences  with  a  whorl  of 
leaves  (Fig.  133,  134)  ;  but  the  subsequent  ones  are 
alternate.  The  Pine,  however  (Fig.  212),  and  the 
Larch,  bear  what  are  termed  2I2 

253.  Fascicled  Leaves.     These  are  really  the  leaves  of  an  axil- 
lary bud.     They  remain  in  a  tuft  or  cluster  because  the  axis  of 

FIG.  211.     Verticillate  or  whorled  leaves  of  a  Galium  or  Bedstraw. 

FIG.  212.  Piece  of  a  branchlet  of  Pitch  Pine,  with  three  leaves  in  a  fascicle  or  bundle,  in 
the  axil  of  a  thin  scale  (a)  which  answers  to  a  primary  leaf.  The  bundle  is  surrounded  at  the 
base  by  a  short  sheath,  formed  of  the  delicate  scales  of  the  axillary  bud. 


VERNATION    OR   PR.EFOLIATION. 


143 


the  bud  does  not  lengthen.  This  is  plainly  seen  in  the  spring 
leaves  of  the  Barberry  and  of  the  Larch  (Fig.  213),  crowded  on 
short  spurs,  some  of  which  soon  elongate  into  ordinary  shoots  with 
scattered  alternate  leaves.  Their 
nature  is  less  evident  in  Pines,  on 
account  of  the  peculiar  character  of 
the  leaves  of  the  main  axis,  from 
whose  axil  the  tuft  of  two,  three,  or 
five  leaves  arises,  the  primary  leaf 
in  this  case  being  a  thin  and  chaffy 
scale  (Fig.  212,  a)  which  soon  falls 
off,  while  the  actual  foliage  all  be- 
longs to  the  axillary  clusters.  So  in  the  common  Barberry  the  prop- 
er leaves  of  the  lengthened  stems  are  chiefly  in  the  form  of  spines 
(Fig.  29G),  and  the  actual  foliage  appears  in  fascicles  in  their  axils. 

254.  As  regards  their  general  position  on  the  stem,  leaves  are  said 
to  be  radical,  when  they  are  borne  on  the  stem  at  or  below  the  sur- 
face of  the  ground,  so  as  apparently  to  grow  from  the  root,  as  those 
of  the  Bloodroot,  Plantain,  Primrose,  and  of  the  acaulescent  (154) 
Violets  :  those  that  arise  along  the  main  stem  are  termed  cauline  ; 
those  of  the  branches,  rameal ;  and  those  which  stand  upon  or  at 
the  base  of  flower-branches  are  called  floral ;  the  latter,  moreover, 
are  generally  termed  bracts. 

255.  With  respect  to  succession,  those  leaves  which  manifestly 
exist  in  the  embryo  are  called  seminal ;  the  first  or  original  pair 
receiving  the  name  of  cotyledons  (120),  and  usually  differing  wide- 
ly in  appearance  from  the  ordinary  leaves  which  succeed  them. 
The  earliest  ordinary  leaves  are  termed  primordial.  These,  as  well 
as  the  cotyledons,  usually  perish  soon  after  others  are  developed  to 
supply  their  place. 

256.  As  pertaining  to  the  arrangement  of  leaves,  we  should  here 
notice  the  modes  in  which  they  are  disposed  before  expansion  in 
the  bud  ;  namely,  their 

257.  Vernation  Or  Pracfoliatioil.  The  latter  is  the  most  character- 
istic name,  but  the  former,  given  by  Linnosus  (literally  denoting 
their  spring  state),  is  the  more  ancient  and  usual.  Two  tilings  are 
included  under  this  head  :  —  1st,  the  mode  in  which  each  leaf  con- 
sidered separately  is  disposed ;  2d,  the  arrangement  of  the  several 


FIG.  213.    Piece  of  a  branchlet  of  the  Larch,  with  two  fascicles  of  leaves. 


144 


THE    LEAVES. 


leaves  of  the  same  bud  in  respect  to  each  other.  This  last  is  evi- 
dently connected  with  phyllotaxis,  or  their  position  and  order  of 
succession  on  the  stem.  As  to  the  first,  leaves  are  for  the  most 
part  either  lent  or  folded,  or  rolled  up  in  vernation.  Thus,  the 
upper  part  may  be  bent  on  the  lower,  so  that  the  apex  of  the  leaf 
is  brought  down  towards  the  base,  as  in  the  Tulip-tree,  when  the 
leaves  are  inflexed  or  reclinate  in  vernation ;  or  the  leaf  may  be 
folded  along  its  midrib  or  axis,  so  that  the  right  half  and  the  left 
half  are  applied  together,  as  in  the  Oak  and  the  Magnolia,  when 
the  leaves  are  conduplicate  ;  or  each  leaf  may  be  folded  up  a  cer- 
tain number  of  times  like  a  fan,  as  in  the  Maple,  Currant,  and  Vine, 
when  they  are  said  to  be  plicate  or  plaited.  The  leaf  may  be 
rolled  either  parallel  with  its  axis,  or  on  its  axis.  In  the  latter  case 
it  is  spirally  rolled  up  from  the  apex  towards  the  base,  like  a  crosier, 
or  circinnate,  as  in  true  Ferns  (Fig.  100),  and  among  Phamoga- 
mous  plants  in  the  Drosera  or  Sundew.  Of  the  former  there  are 
three  ways  ;  viz.  the  whole  leaf  may  be  laterally  rolled  up  from  one 
edge  into  a  coil,  with  the  other  edge  exterior,  when  the  leaves  are 
said  to  be  convolute,  as  in  the  Apricot  and  Cherry ;  or  both  edges 
may  be  equally  rolled  towards  the  midrib ;  either  inwards,  when 
they  are  involute,  as  in  the  Violet  and  the  "Water-Lily  ;  or  else  out- 
wards, when  they  are  revolute,  as  in  the  Eosemary  and  Azalea.  Fig. 
214-219  are  Linnasan  diagrams  of  sections  of  leaves,  illustrating 
the  principal  modes  of  vernation. 

258.  Considered  relatively  to  each  other,  leaves  are  valvate  in 

vernation  when  corresponding  ones  touch  each  other  by  their  edges 

214  215  2i6  only,  Avithout  overlap- 

s^.       ft        A  ^- — ^         phig:  they  are  imbri- 

/f^  \  *9  /T\\       cated  when  the  outer 

C&?  ^l/LSN*  \w^-*^/       successively      overlap 

the  inner,  by  then- 
edges  at  least,  in  which 
case  the  order  of  over- 
lapping exhibits  the 
phyllotaxis,  or  order 
of  succession  and  po- 
sition. In  these  cases 
the  leaves  are  plane  or  convex,  or  at  least  not  much  bent  or  rolled. 

FIG.  214.     Conduplicate  ;   215.  Plicate  or  plaited ;   216.   Convolute ;   217.  Revolute  ;   218. 
Involute  ;  and,  219.  Circmate,  vernation. 


THEIR    STRUCTURE    AND    CONFORMATION.  145 

When  leaves  with  their  margins  involute  are  applied  together  in  a 
circle  without  overlapping,  the  vernation  is  induplicate.  When,  in 
conduplicate  leaves,  the  outer  successively  embrace  or  sit  astride  of 
those  next  within,  the  vernation  is  equitant,  as  the  leaves  of  the  Iris 
at  their  base  (Fig.  296)  ;  or  when  each  receives  in  its  fold  the  half 
of  a  corresponding  leaf  folded  in  the  same  manner,  the  vernation  is 
half-equitant  or  obvolute.  These  terms  equally  apply  to  leaves  in 
their  full-grown  condition,  whenever  they  are  then  so  situated  as  to 
overlie  or  embrace  one  another.  They  likewise  apply  to  the  parts 
in  the  flower-bud,  under  the  name  of  aestivation  or  prrefloration. 
Chap.  IX.  Sect.  V. 


Sect.  II.     Their  Structure  and  Conformation. 

259.  Anatomy  Of  the  Leaf.  The  complete  leaf  consists  of  the 
Blade  {Lamina  or  Limb,  Fig.  229,  b),  with  its  Petiole  or  Leaf- 
stalk, p,  and  at  its  base  a  pair  of  Stipules,  st.  Of  these  the  latter 
are  frequently  absent  altogether,  and  in  many  cases  where  they 
originally  exist  they  fall  away  as  the  leaf  expands.  The  petiole  is 
very  often  wanting ;  when  the  leaf  is  sessile,  or  has  its  blade  rest- 
ing immediately  on  the  stem  that  bears  it  (as  in  Fig.  210,  211). 
Sometimes,  moreover,  there  is  no  proper  blade,  but  the  whole  organ 
is  cylindrical  or  stalk-like.  It  is  the  general  characteristic  of  the  leaf, 
however,  that  it  is  an  expanded  body.  Indeed,  it  may  be  viewed  as 
a  contrivance  for  increasing  the  green  surface  of  a  plant,  so  as  to 
expose  to  the  light  and  air  the  greatest  practicable  amount  of  paren- 
chyma containing  the  green  matter  of  vegetation  (chlorophyll,  92), 
upon  which  the  light  exerts  its  peculiar  action.  Leaves  as  foliage, 
accordingly,  are  what  Ave  are  now  principally  to  consider 

260.  In  a  general,  mechanical  way,  it  may  be  said  leaves  are  defi- 
nite protrusions  of  the  green  layer  of  the  bark,  expanded  horizon- 
tally into  a  thin  lamina,  and  stiffened  by  tough,  woody  fibres  (con- 
nected both  with  the  liber,  or  inner  bark,  and  the  wood),  which  form 
its  framework,  ribs,  or  veins.  Like  the  stem,  therefore,  the  leaf  is 
made  up  of  two  distinct  parts,  the  cellular  and  the  woody.  The 
cellular  portion  is  the  green  pulp  or  parenchyma :  the  woody,  is  the 
skeleton  or  framework  which  ramifies  among  and  strengthens  the 
former.  The  woody  or  fibrous  portion  fulfils  the  same  purposes  in 
the  leaf  as  in  the  stem,  not  only  giving  firmness  and  support  to  the 

13 


146 


THE     LEAVES. 


delicate  cellular  apparatus,  but  also  serving  for  the  conveyance  and 
distribution  of  the  sap.  The  subdivision  of  these  ribs,  or  veins,  of 
the  leaf,  as  they  are  not  inappropriately  cajled,  continues  beyond 
the  limits  of  unassisted  vision,  until  the  bundles  or  threads  of  woody 
tissue  are  reduced  to  very  delicate  fibres,  ramified  throughout  the 
green  pulp. 

261.  The  cellular  portion  of  the  leaf  consists  of  thin-walled  cells 
of  loose  parenchyma,  containing  grains  of  chlorophyll,  to  which 
the  green  color  of  foliage  is  entirely  owing.  The  cells  are  not 
heaped  promiscuously,  but  exhibit  a  regular  arrangement ;  upon  a 
plan,  too,  which  varies  in  different  parts  of  the  leaf,  according  to  the 
different  conditions  in  which  it  is  placed. 

262.  Leaves  are  almost  always  expanded  horizontally,  so  as  to 
present  one  surface  to  the  ground  and  the  other  to  the  sky ;  and 
the  parenchyma  forms  two  general  strata,  one  belonging  to  the 
upper  and  the  other  to  the  lower  side.  The  microscope  displays  a 
manifest  difference  in  the  parenchyma  of  these  two  strata.  That 
of  the  upper  stratum  is  composed  of  one  or  more  compact  layers  of 
oblong  cells,  placed  endwise,  or  with  their  long  diameter  perpen- 
dicular to  the  surface  ;  while  that  of  the  lower  stratum  is  very  loosely 
arranged,  leaving  numerous  vacant  spaces  between  the  cells  ;  and 
when  the  cells  are  oblong,  their  longer  diameter  is  parallel  with  the 
epidermis.  This  is  shown  in  Fig.  7,  which  represents  a  magnified 
section  through  the  thickness  (perpendicular  to  the  surface)  of  a 
leaf  of  the   Star-Anise  of  Florida ;    where   the   upper  stratum  of 

parenchyma  consists  of  only  a 
single  series  of  perpendicular 
cells.  Also  in  Fig.  220,  which 
represents  a  similar  view  of  a 
thin  slice  of  a  leaf  of  the  Gar- 
den Balsam.  Fig.  221  repre- 
sents a  piece  cut  out  of  a  leaf 
of  the  White  Lily ;  where  the 
upper  stratum  is  composed  of 
only  one  compact  layer  of  ver- 
tical cells.  The  parenchyma  is  alone  represented ;  the  woody  por- 
tion, or  veins,  being  left  out.     The  more  compact  structure  of  the 


FIG.  220.  magnified  section  through  the  thickness  of  a  leaf  of  the  Garden  Balsam  :  a,  sec- 
tion of  the  epidermis  of  the  upper  surface  ;  6,  of  the  upper  stratum  of  parenchyma  ;  c,  of  the 
lower  stratum  ;  d,  of  the  epidermis  of  the  lower  surface.    (After  Brongniart.) 


THEIR   ANATOMICAL    STRUCTURE. 


147 


upper  stratum  shows  why  the  upper  surface  of  leaves  is  of  a  deeper 
green  than  the  lower. 

263.  The  object  which  this  arrangement  subserves  will  appear 
evident,  when  we  consider  that  the  spaces  between  the  cells,  filled 
with  air,  communicate  freely  with  each  other  throughout  the  leaf, 
and  also  with  the  external  air  by  means  of  openings  in  the  epider- 
mis (presently  to  be  described)  ;  and  when  Ave  consider  the  powerful 
action  of  the  sun  to  promote  evaporation,  especially  in  dry  air ;  and 
that  the  thin  walls  of  the  cells,  like  all  vegetable  membrane,  allow 
of  the  free  escape  of  the  contained  moistiu*e  by  transudation.  The 
compactness  of  the  cells  of  that  stratum  which  is  pi'esented  immedi- 
ately to  the  sun,  and  their  vertical  elongation,  so  that  each  shall 
expose  the  least  possible  surface,  obviously  serve  to  protect  the 
loose  parenchyma  beneath  from  the  too  powerful  action  of  direct 
sunshine.  This  provision  is  the  more  complete  in  the  case  of  plants 
which  retain  their  foliage  through  a  season  of  drought  in  arid  re- 
gions, where  the  soil  is  usually  so  parched  during  the  dry  season, 
that,  for  a  long  period,  it  affords  only  a  scanty  supply  of  moisture  to 
the  roots.  Compare,  in  this  respect,  a  leaf  of  the  Lily  (Fig.  221), 
where  the  upper  stratum  contains  but  a  single  layer  of  barely  oblong 
cells,  with  the  firm  and  more  enduring  leaf  of  the  Oleander,  the 


upper  stratum  of  which  consists  of  two  layers  of  long  and  narrow 
vertical  cells  as  closely  compacted  as  possible  (Fig.  222).     So  dif- 

FIG.  221.     A  magnified  section  through  the  thickness  of  a  minute  piece  of  the  leaf  of  the 
White  Lily  of  the  gardens,  showing  also  a  portion  of  the  under  side  with  some  breathing-pores. 


148 


THE    LEAVES. 


ferent  is  the  organization  of  the  two  strata,  that  a  leaf  soon  perishes 
if  reversed  so  as  to  expose  the  lower  surface  to  direct  sunshine. 

264.  A  further  and  more  effectual  provision  for  restraining  the 
perspiration  of  leaves  within  due  limits  is  found  in  the  Epidermis, 
or  skin,  that  invests  the  leaf,  as  it  does  the  whole  surface  of  the  vege- 
table (69),  and  which  is  so  readily  detached  from  the  succulent  leaves 
of  such  plants  as  the  Stonecrop  and  the  Live-for-ever  (Sedum)  of 
the  gardens.  The  epidermis  is  composed  of  small  cells  belonging  to 
the  outermost  layer  of  cellular  tissue,  with  the  pretty  thick-sided 
walls  very  strongly  coherent,  so  as  to  form  a  firm  membrane.  Its 
cells  contain  no  chlorophyll.  In  ordinary  herbs  that  allow  of  ready 
evaporation,  this  membrane  is  made  up  of  a  single  layer  of  cells  ;  as 
in  the  Lily,  Fig.  221,  and  the  Balsam,  Fig.  220.  It  is  composed  of 
two  layers  in  cases  where  one  might  prove  insufficient ;  and  in  the 
Oleander,  besides  the  provision  against  too  copious  evaporation, 
already  described  (263),  the  epidermis  consists  of  three  com- 
pact layers  of  very  thick-sided 
cells  (Fig.  222).  It  is  generally 
thick,  or  hard  and  impermeable, 
in  the  firm  leaves  of  the  Pitto- 
sporum,  Laurustinus,  and  other 
plants,  which  will  thrive,  for  this 
very  reason,  where  those  of  more  delicate  foliage  are  liable  to  per- 
ish, in  the  dry  atmosphere  of  our  rooms  in  winter. 


FIG  222.  Magnified  section  through  a  part  only  of  the  thickness  of  a  leaf  of  the  Oleander, 
showing  the  epidermis  of  the  upper  surface,  formed  of  three  layers  of  thick-walled  cells  and 
the  two  very  compact  layers  of  cylindrical  cells  standing  endwise. 

FIG.  223.  Magnified  slice  of  the  epidermis  and  superficial  parenchyma  of  a  Cactus,  after 
Schleiden  ;  exhibiting  the  epidermis  (a)  greatly  thickened  by  a  stratified  deposition  in  the  cells  : 
and  some  cells  of  the  parenchyma  likewise  nearly  filled  with  an  incrusting  deposit.  The  depo- 
sition in  such  cases  is  always  irregular,  leaving  canals  or  passages  which  nearly  connect  the 
adjacent  cells.     Several  of  the  cells  contain  crystals  (94). 

FIG.  224.  Similar  section  from  another  species  of  Cactus,  passing  through  one  of  the  sto- 
mata,  and  the  deep  intercellular  space  beneath  it. 


THEIR   ANATOMICAL    STRUCTURE.  149 

265.  In  such  firm  leaves,  especially,  the  walls  of  the  epidermal 
cells  are  soon  thickened  by  internal  deposition  (44),  especially 
on  the  superficial  side.  This  is  well  seen  in  the  epidermis  of  the 
Aloe,  and  in  other  fleshy  plants,  Avhich  hear  severe  drought  with 
impunity :  in  Fig.  223,  it  is  shown,  at  a,  in  the  rind  of  a  Cactus, 
in  which  the  green  layer  of  the  whole  stem  answers  the  purpose 
of  leaves.  Sometimes  an  exterior  layer  of  this  superficial  deposit 
in  the  epidermis  may  be  detached  in  the  form  of  a  continuous,  ap- 
parently structureless  membrane,  which  Brongniart  and  succeeding 
authors  have  called  the  Cuticle.  That  it  may  shed  water  readily, 
the  surface  of  leaves  is  commonly  protected  by  a  very  thin  varnish 
of  wax,  or  else  with  a  bloom  of  the  same  substance  in  the  form  of  a 
whitish  powder,  which  easily  rubs  off  (85),  as  is  familiarly  seen  in  a 
Cabbage-leaf. 

266.  A  thickening  deposit  sometimes  takes  place  in  the  cells  of 
parenchyma  immediately  underneath  the  epidermis,  especially  in 
the  Cactus  Family,  where  the  once  thin  and  delicate  walls  of  the 
cells  become  excessively  and  irregularly  thickened  (Fig.  223,  224), 
so  as  doubtless  to  arrest  or  greatly  obstruct  exhalation  through  the 
rind.  Something  like  this  choking  of  the  cells  mustf  commonly 
occur  with  age  in  most  leaves,  particularly  those  that  live  for  more 
than  one  season  (311). 

267.  But  the  multiplication  of  these  safeguards  against  exhalation 
might  be  liable  to  defeat  the  very  objects  for  which  leaves  are  prin- 
cipally destined.  Evaporation  from  the  parenchyma  of  the  leaves 
is  essential  to  the  plant,  as  it  is  the  only  method  by  which  its  exces- 
sively dilute  food  can  be  concentrated.  Some  arrangement  is  requi- 
site that  shall  allow  of  sufficient  exhalation  from  the  leaves  while 
the  plant  is  freely  supplied  with  moisture  by  the  roots,  but  restrain 
it  when  the  supply  is  deficient.  It  is  clear  that  the  greatest  demand 
is  made  upon  the  leaves  at  the  very  period  when  the  supply  through 
the  roots  is  most  likely  to  fail ;  for  the  summer's  sun,  which  acts  so 
powerfully  on  the  leaves,  at  the  same  time  parches  the  soil  upon 
which  the  leaves  (through  the  rootlets)  depend  for  the  moisture  they 
exhale.  So  long  as  their  demands  are  promptly  answered,  all  goes 
well.  The  greater  the  force  of  the  sun's  rays,  the  greater  the  speed 
at  which  the  vegetable  machinery  is  driven.  But  whenever  the 
supply  at  the  root  fails,  the  foliage  begins  to  flag  and  droop,  as  is  so 
often  seen  under  a  sultry  meridian  sun  ;  and  if  the  exhaustion  pro- 
ceeds beyond  a  certain  point,  the  leaves  inevitably  wither  and  perish. 

13* 


150  THE    LEAVES. 

Some  adaptation  is  therefore  needed,  analogous  to  a  self-acting  valve, 
which  shall  regulate  the  exhalation  according  to  the  supply.  Such 
an  office  is  actually  fulfilled  by 

268.  The  Stomata,  Stomates,  or  Breathing-pores  (70).  Through 
the  orifices  which  bear  this  name,  exhalation  principally  takes  place, 
in  all  ordinary  cases,  where  the  epidermis  is  thick  and  firm  enough 
to  prevent  much  escape  of  moisture  by  direct  transudation.     The 

stomata  (Fig.  225-228)  are  always  so 
situated  as  to  open  directly  into  the  hol- 
low chambers,  or  air-cavities,  which 
pervade  the  parenchyma  (Fig.  221), 
especially  the  lower  stratum,  so  as  to 
afford  free  communication  between  the 
external  air  and  the  whole  interior  of 
the  leaf.  The  perforation  of  the  epi- 
235  dermis  is  between  two  (or  rarely  four) 

delicate  and  commonly  crescent-shaped  cells,  which,  unlike  the  rest 
of  the  epidermis,  usually  contain  some  chlorophyll,  and  in  other  re- 
spects resemble  the  parenchyma  beneath.  When  moistened  these 
guardian-cefls  change  their  form,  becoming  more  crescentic  as  they 
become  more  turgid,  thereby  separating  in  the  middle  and  opening  a 
free  communication  between  the  outer  air  and  the  interior  of  the 
leaf.  As  they  become  drier,  they  shorten  and  straighten,  so  as  to 
bring  the  sides  of  the  two  into  contact  and  close  the  orifice.*  The 
use  of  tliis  mechanism  will  be  readily  understood.    So  long  as  the  leaf 

*  They  expand  and  contract  most  in  the  direction  of  their  length ;  and  the 
elongation  and  increased  curvature  when  moist  draws  in  the  concave  side  and 
so  enlarges  the  aperture.  The  mechanism  of  the  opening  and  shutting  of  sto- 
mata has  been  recently  investigated  by  Mohl  (in  Bot.  Zeitung  for  1856,  p.  697, 
—  an  abstract  of  the  memoir  is  given  by  C.  F.  Stone  in  Amer.  Journal  of  Sci- 
ence for  March,  1857),  —  and  these  facts  verified.  The  peculiar  change  of  the 
guardian-cells  in  form  seems  not  entirely  susceptible  of  mechanical  explanation, 
and  is  partly  controlled  (like  other  vegetable  movements)  by  the  light  of  the 
sun ;  but  it  mainly  depends  upon  endosmose.  Mohl  has  clearly  shown  that, 
while  the  guardian-cells  themselves  act  so  as  to  open  the  stomate  in  moisture 
and  close  it  in  dryness,  the  adjacent  cells  of  the  epidermis  in  swelling  when 
moist  tend  to  close  the  stomate,  and  their  contraction  when  dry  to  open  it ;  — 
so  that  the  actual  position  at  any  time  is  a  resultant  of  nicely  adjusted  opposing 
forces. 

FIG.  225.  A  highly  magnified  piece  of  the  epidermis  of  the  Garden  Balsam,  -with  three 
stomata  (after  Brongniart). 


THEIR    STOMATA    OR    BREATHING-PORES. 


151 


is  in  a  moist  atmosphere,  and  is  freely  supplied  with  sap,  the  sto- 
mates  remain  open,  and  allow  the  free  escape  of  moisture  by  evap- 
oration. But  when  the  supply  fails,  and  the  parenchyma  begins  to 
be  exhausted,  the  guardian-cells,  at  least  equally  affected  by  the  dry- 
ness, promptly  collapse,  and  by  closing  these  thousands  of  apertures 
check  the  drain  the  moment  it  becomes  injurious  to  the  plant. 

269.  As  a  general  rule,  the  stomata  wholly  or  principally  belong 
to  the  epidermis   of  the  lower 

surface  of  the  leaf:  the  mechan- 
ism is  too  delicate  to  work  well 
in  direct  sunshine.  The  posi- 
tion of  the  stomata,  and  the 
loose  texture  of  the  lower  pa- 
renchyma, require  that  this  sur- 
face should  be  shielded  from  the  sun's  too  direct  and  intense  action ; 
and  show  why  leaves  soon  perish  when  artificially  reversed,  and  pre- 
vented from  resuming  (as  otherwise  they  spontaneously  will)  their 
natural  position.  This  general  arrangement  is  vai'iously  modified, 
however,  under  peculiar  circumstances.  The  stomata  are  equally 
distributed  on  the  two  sides  of  those  leaves,  of  whatever  sort, 
which  grow  in  an  erect  position,  or  present  their  edges,  instead  of 
their  surfaces,  to  the  earth  and  sky  (294),  and  have  the  parenchyma 
of  both  sides  similarly  constituted,  sustaining  consequently  the  same 
relations  to  light.  In  the  Water-Lilies  (Nymphosa,  Nuphar),  and 
other  leaves  which  float  upon  the  water,  the  stomata  all  belong  to 
the  upper  surface.  All  leaves  which  live  under  water,  where  there 
can  be  no  evaporation,  are  destitute,  not  only  of  stomata,  but  usually 
of  a  distinct  epidermis  also. 

270.  The  number  of  the  stomata  varies  in  different  leaves  from 
800  to  about  170,000  on  the  square  inch  of  surface.  In  the  Apple, 
there  are  said  to  be  about  24,000  to  the  square  inch  (which  is  under 
the  average  number,  as  given  in  a  table  of  36  species  by  Lindley)  ; 
so  that  each  leaf  of  that  tree  would  present  about  100,000  of  these 
orifices.  When  the  stomata  are  not  all  restricted  to  the  lower  sur- 
face, still  the  greater  portion  usually  occupy  this  position.  Thus, 
the  leaf  of  Arum  Dracontium  is  said  to  have  8,000  stomata  to  a 
square  inch  of  the  upper  surface,  and  twice  that  number  in  the 


FIG.  226.  Magnified  view  of  the  10,000th  part  of  a  square  inch  of  the  epidermis  of  the 
lower  surface  of  the  leaf  of  the  White  Lily,  with  its  stomates.  227.  A  single  stomate,  more 
magnified.    228.  Another  stomate,  widely  open. 


152  THE    LEAVES. 

same  space  of  the  lower.  The  leaf  of  the  Coltsfoot  has  12,000 
stomata  to  a  square  inch  of  the  lower  epidermis,  and  only  1,200  in 
the  upper.  That  of  the  White  Lily  has  from  20,000  to  G0,000  to 
the  square  inch  on  the  lower  surface,  and  perhaps  3,000  on  the  up- 
per. In  this  plant,  and  in  other  true  Lilies,  they  are  so  remarkably 
large  (Fig.  221,  226  —  228)  that  they  may  he  discerned  by  a  simple 
lens  of  an  inch  focus.  In  most  plants  they  are  very  much  smaller 
than  this. 

271.  Succulent  or  fleshy  plants,  such  as  those  of  the  Cactus  tribe, 
Mesembryanthemums,  Sedums,  Aloes,  &c.,are  remarkable  for  holding 
the  water  they  imbibe  with  great  tenacity,  rather  in  consequence  of 
the  thickness  of  the  epidermis,  or  from  the  deposit  which  early  ac- 
cumulates in  the  superficial  cells  of  the  parenchyma  (2GG),  than 
from  the  want  of  stomata.  The  latter  are  usually  abundant,*  but 
they  seem  to  open  less  than  in  ordinary  plants,  except  in  young  and 
growing  parts.  Hence  the  tissue  becomes  gorged  as  it  were  with 
fluid,  which  is  retained  with  great  tenacity,  especially  during  the 
hot  season.  They  are  evidently  constructed  for  enduring  severe 
droughts  ;  and  are  accordingly  found  to  inhabit  dry  and  sunburnt 
places,  such  as  the  arid  plains  of  Africa,  —  the  principal  home  of  the 
Stapelias,  Aloes,  succulent  Euphorbias,  &c,  —  or  the  hottest  and 
driest  parts  of  our  own  continent,  to  which  the  whole  Cactus  family 
is  indigenous.  Or,  when  such  plants  inhabit  the  cooler  temperate 
regions,  like  the  Sedums  and  the  common  Houseleek,  &c,  they  are 
commonly  found  in  the  most  arid  situations,  on  naked  rocks,  old 
walls,  or  sandy  plains,  exposed  to  >the  fiercest  rays  of  the  noonday 
sun,  and  thriving  where  ordinary  plants  would  speedily  perish.  The 
drier  the  atmosphere,  the  greater  their  apparent  reluctance  to  part 
with  the  fluid  they  have  accumulated,  and  upon  which  they  live 
during  the  long  period  when  little  or  no  moisture  is  yielded  by  the 
soil  or  the  air.  Their  structure  and  economy  fully  explain  their 
tolerance  of  the  very  dry  air  of  our  houses  in  midwinter,  when  or- 
dinary thin-leaved  plants  become  unhealthy  or  perish. 

272.  Sometimes  the  leaves  of  succulent  plants  merely  become 
obese  or  misshapen,  like  those  of  the  Ice-plant  and  other  species 


*  The  thickened  epidermis  of  the  fleshy  leaves  of  the  Sea-Sand  wort  (Hon- 
kenya)  is  provided  with  an  abundance  of  large  stomata,  on  the  upper  as  well 
as  the  lower  face.  But  this  plant,  though  very  fleshy,  grows  in  situations  where 
its  roots  are  always  supplied  with  moisture. 


THEIR    DEVELOPMENT,    ETC.  153 

of  Mesembryanthemum,  &c. :  sometimes  they  are  reduced  to  tri- 
angular projections  or  points,  or  are  perfectly  confounded  with  the 
green  bark  of  the  stem,  which  fulfils  their  office,  as  in  the  Stapelia 
and  most  Cacti. 

273.  The  Development  of  leaves.  At  their  first  appearance,  each 
leaf  is  a  minute  papilla  or  projection  of  parenchyma  on  the  nascent 
axis  :  as  it  grows,  this  shapes  itself  into  the  blade,  and  is  eliminated 
from  the  axis.  The  petiole,  if  any,  is  later  formed,  and  by  its 
growth  raises  the  blade  from  the  stem.  Commonly  the  apex  of  the 
blade  first  appears,  and  the  formation  proceeds  from  above  down- 
wards. The  sheath  at  the  base  (as  in  most  Monocotyledons),  or 
the  stipules  (259,  which  principally  belong  to  Dicotyledons),  are  at 
first  continuous  with  the  blade,  or  divided  from  it  by  a  mere  con- 
striction :  the  formation  and  elongation  of  the  petiole  soon  separate 
them.  The  stipules,  remaining  next  the  axis  or  source  of  nourish- 
ment, undergo  a  rapid  development  early  in  the  bud,  so  that,  at  a 
certain  stage,  they  are  often  larger  than  the  body  of  the  leaf,  and 
they  accordingly  form  in  such  cases  the  teguments  of  the  bud. 
Divided  or  lobed  and  compound  leaves  are  simple  at  the  commence- 
ment, but  the  lobes  are  very  early  developed ;  they  grow  in  respect 
to  the  axis  of  the  leaf  nearly  as  that  grew  from  the  axis  of  the 
plant,  and  in  the  compound  leaf  at  length  isolate  themselves,  and 
are  often  raised  on  footstalks  of  their  own.  Commonly  the  upper 
lobes  or  leaflets  are  first  formed,  and  then  the  lower :  but  in  those 
of  the  TValnut  and  Ailanthus,  and  other  large  compound  leaves,  the 
formation  proceeds  from  below  upwards,  and  new  leaflets  continue 
to  be  produced  from  the  apex,  even  after  the  lowermost  are  nearly 
full  grown.  In  the  earliest  stage  leaves  consist  of  parenchyma 
alone:  the  fibro-vascular  tissue  which  makes  the  ribs,  veins,  or 
framework  appears  later. 

274.  At  the  points  on  the  surface  of  the  developing  leaf  where 
stomata  are  about  to  be  formed,  one  of  the  epidermal  cells  early 
ceases  to  enlarge  and  thicken  with  the  rest,  but  divides  into  two  (in 
the  manner  formerly  described,  33),  forming  the  two  guardian-cells 
of  the  stomate  :  as  they  grow,  the  two  constituent  portions  of  their 
common  partition  separate,  leaving  an  interspace  or  orifice  between. 
In  some  cases,  each  new  cell  divides  again,  when  the  stomate  is 
formed  of  four  cells  in  place  of  two. 

275.  The  Forms  Of  Leaves  are  almost  infinitely  various.  These 
afford   some  of  the    readiest,  if  not  the  most  certain,  marks  for 


154  THE    LEAVES. 

characterizing  species.  Their  principal  modifications  are  therefore 
classified,  minutely  defined,  and  embodied  in  a  system  of  nomen- 
clature which  is  equally  applicable  to  other  parts  of  the  plant,  and 
which  as  an  instrument  is  indispensable  to  the  systematic  botanist. 
The  numerous  technical  terms  which  have  gradually  accumulated 
from  the  infancy  of  the  science,  and  have  multiplied  with  its  increas- 
ing wants,  are  mostly  quite  arbitrary,  or  have  been  suggested  by 
real  or  fancied  resemblances  of  their  shapes  to  various  natural  or 
other  objects.  This  arbitrary  nomenclature,  which  formerly  severe- 
ly tasked  the  memory  of  the  student,  was  reduced  by  De  Candolle 
to  a  clear  and  consistent  system,  based  upon  scientific  principles, 
and  of  easy  application.  The  fundamental  idea  of  the  plan  is,  that 
the  almost  infinite  varieties  in  the  form  and  outline  of  leaves  may 
be  deduced  from  the  different  modes  and  degrees  in  which  the 
woody  skeleton  or  framework  of  the  leaf  is  expanded  or  ramified 
in  the  parenchyma.  Upon  this  conception  the  following  sketch  is 
based ;  in  which  all  the  more  important  terms  of  the  nomenclature 
of  leaves  are  mentioned  and  defined.  It  should  be  kept  in  mind, 
however,  that  this  is  not  to  be  taken  as  an  explanation  of  the  actual 
formation  of  leaves  ;  but  rather  as  an  account  of  the  mutual  adap- 
tation and  correspondence  of  their  outlines  and  framework.  For 
the  parenchyma  is  developed,  and  the  form  of  the  leaf  more  or  less 
determined,  before  the  framework  has  an  existence.  The  latter, 
therefore,  cannot  have  given  rise  to  the  outline  or  shape  of  the 
organ.  Tbe  distribution  of  the  veins  or  fibrous  framework  of  the 
leaf  in  the  blade  is  termed  its 

27G.  Venation.  The  veins  are  distributed  throughout  the  lamina 
in  two  principal  modes.  Either  the  vessels  of  the  petiole  divide  at 
once,  where  they  enter  the  blade,  into  several  veins,  which  run 
parallel  with  each  other  to  the  apex,  connected  only  by  simple 
transverse  veinlets  (as  in  Fig.  230)  ;  or  the  petiole  is  continued 
into  the  blade  in  the  form  of  one  or  more  principal  or  coarser 
veins,  which  send  off  branches  on  both  sides,  the  smaller  branch- 
lets  uniting  with  one  another  {anastomosing)  and  forming  a  kind 
of  network ;  as  in  Fig.  229.  The  former  are  termed  parallel- 
veined,  or  commonly  nerved  leaves  ;  the  veins  in  this  case  having 
been  called  nerves  by  the  older  botanists,  —  a  name  which  it  is 
found  convenient  to  retain,  although  of  course  they  are  in  no  respect 
analogous  to  the  nerves  of  animals.  The  latter  are  termed  reticu- 
lated or  netted-veined  leaves. 


THEIR    VENATION. 


155 


277.  Parallel-veined  or  nerved  leaves  are  characteristic  of  En- 
dogenous  plants  ;  while  reticulated  leaves  are  almost  universal  in 


Exogenous  plants.  We  are  thus  furnished  with  a  very  obvious,  al- 
though by  no  means  absolute,  distinction  between  these  two  great 
classes  of  plants,  independently  of  the  structure  of  their  stems  (198). 
278.  In  reticulated  leaves,  the  coarse  primary  veins  (one  or 
more  in  number),  which  proceed  immediately  from  the  apex  of  the 
petiole,  are  called  ribs ;  the  branches  are  termed  veins,  and  their 
subordinate  ramifications,  veinlets.  Very  frequently,  a  single  strong 
rib  (called  the  midrib),  forming  a  continuation  of  the  petiole,  runs 
directly  through  the  middle  of  the  blade  to  the  apex  (Fig.  229,  238, 
&c),  and  from  it  the  lateral  veins  all  diverge.  Such  leaves  are 
termed  feather-veined  or  pinnately  veined ;  and  are  subject  to  vari- 
ous modifications,  according  to  the  arrangement  of  the  veins  and  vein- 
lets  ;  the  primary  veins  sometimes  passing  straight  from  the  midrib 
to  the  margin,  as  in  the  Beech  and  Chestnut  (Fig.  238)  ;  while 
in  other  cases  they  are  divided  into  veinlets  long  before  they  reach 
the  margin.  When  the  midrib  gives  off  a  very  strong  primary  vein 
or  branch  on  each  side  above  the  base,  the  leaf  is  said  to  be  triple- 
ribbed,  or  often  tripli-nerved,  as   in  the   common   Sunflower   (Fig. 

FIG.  229.     A  leaf  of  the   Quince,  of  the  netted-vcined  or  reticulated  sort :    b,  blade : 
p,  petiole  or  leaf -stalk  :  st,  stipules. 

FIG.  230.    Parallel-  veined  leaf  of  the  Lily  of  the  Valley. 


156 


THE    LEAVES. 


241)  ;  if  two  such  ribs  proceed  from  each  side  of  the  midrib,  it  is 
said  to  be  quintuple-ribbed,  or  quintupli-nerved. 


279.  Not  unfrequently  the  vessels  of  a  reticulated  leaf  divide  at 
the  apex  of  the  petiole  into  three  or  more  portions  or  ribs  of  nearly- 
equal  size,  which  are  usually  divergent,  each  giving  off  veins  and 
veinlets,  like  the  single  rib  of  a  feather-veined  leaf.  Such  leaves 
are  termed  radiated-veined,  or  palmately-veined  ;  and,  as  to  the 
number  of  the  ribs,  are  called  three-ribbed,  five-ribbed,  seven-ribbed, 
&c.  (Fig.  244,  247,  253).  Examples  of  this  form  are  furnished  by 
the  Maple,  the  Gooseberry,  the  Mallow  family,  &c.  Occasionally 
the  ribs  of  a  radiated-veined  leaf  converge  and  run  to  the  apex  of  the 
blade,  as  in  Rhexia  and  other  plants  of  the  same  family,  thus  resem- 
bling a  parallel-veined  or  nerved  leaf;  from  which,  however,  it  is 
distinguished  by  the  intermediate  netted  veins.  But  when  the  ribs 
are  not  very  strong,  such  leaves  are  frequently  said  to  be  nerved, 
although  they  branch  before  reaching  the  apex. 

280.  According  to  the  theory  of  De  Candolle  (275),  the  shape 
which  leaves  assume  may  be  viewed  as  dependent  upon  the  dis- 
tribution of  the  veins,  and  the  quantity  of  parenchyma ;  the  gen- 
eral outline  being  determined  by  the  division  and  direction  of  the 
veins  ;  and  the  form  of  the  margin,  (whether  even  and  continuous, 
or  else  interrupted  by  void  spaces  or  indentations,)  by  the  greater  or 

FIG.  231-244.    Various  forms  of  simple  leaves. 


THKIR    FORMS. 


157 


less  abundance  of  the  parenchyma  in  which  the  veins  are  distrib- 
uted.    This  view  is  readily  intelligible  upon  the  supposition  that  a 

245  247  248 


'    /V~-JSt~~. 


leaf  is  an  expansion  of  soft  parenchyma,  in  which  the  firmer  veins 
are  variously  ramified.  Thus,  if  the  principal  veins  of  a  feather- 
veined  leaf  are  not  greatly  prolonged,  and  are  somewhat  equal  in 
length,  the  blade  Avill  have  a  more  or  less  elongated  form.  If  the 
veins  are  very  short  in  proportion  to  the  midrib,  and  equal  in  length, 
the  leaf  will  be  linear  (as  in  Fig.  240)  ;  if  longer  in  proportion, 
but  still  equal,  the  leaf  will  assume  an  oblong  form  (Fig.  242), 
which  a  slight  rounding  of  the  sides  converts  into  an  oval  or  ellip- 
tical outline.  If  the  veins  next  the  base  are  longest,  and  especially 
if  they  curve  forward  towards  their  extremities,  the  leaf  assumes  a 
lanceolate  (Fig.  239),  ovate  (Fig.  241),  or  some  intermediate  form. 
On  the  other  hand,  if  the  veins  are  more  developed  beyond  the  mid- 
dle of  the  blade,  the  leaf  becomes  obovate  (Fig.  232),  or  cuneiform 
(Fig.  235).  In  radiated  or  palmately  veined  leaves  (Fig.  245-253), 
where  the  primary  ribs  are  divergent,  an  orbicular  or  roundish  out- 
line is  most  common.  When  some  of  the  ribs  or  their  ramifications 
are  directed  backwards,  a  recess,  or  sinus,  as  it  is  termed,  is  pro- 
duced at  the  base  of  the  leaf,  which,  taken  in  connection  with  the 
general  form,  gives  rise  to  such  terms  as  cordate  or  heart-shaped 
(Fig.  244),  reniform  or  kidney-shaped  (Fig.  245),  &c,  when  the 
posterior  portions  are  rounded ;  and  those  of  sagittate  or  arrow- 
headed  (Fig.  252),  and  hastate  or  halberd-shaped  (Fig.  250),  when 

FIG.  245  -  253.     Forms  of  simple,  chiefly  radiated-veined  leaves. 

14 


158  THE    LEAVES. 

the  angles  or  lobes  at  the  base  diverge.  The  margins  of  the  sinus 
are  sometimes  brought  into  contact  and  united,  when  the  leaf  be- 
comes peltate  or  shield-shaped  (Fig.  248)  ;  the  blade  being  attached 
to  the  petiole,  not  by  its  apparent  base,  but  by  some  part  of  the 
lower  surface.  Two  or  three  common  species  of  Hydrocotyle 
plainly  exhibit  the  transition  from  common  radiated  leaves  into  the 
peltate  form.  Thus,  the  leaf  of  H.  Americana  (Fig.  247)  is  round- 
ish-reniform,  with  an  open  sinus  at  the  base,  while  in  H.  inter- 
rupta  and  H.  umbellata  (Fig.  248),  the  margins  have  grown  to- 
gether so  as  to  obliterate  the  sinus,  and  an  orbicular  peltate  leaf  is 
produced.  In  nerved  leaves,  when  the  nerves  run  parallel  from 
the  base  to  the  apex,  as  in  Grasses  (Fig.  237),  the  leaf  is  necessa- 
rily linear,  or  nearly  so ;  but  when  they  are  more  divergent  in  the 
middle,  or  towards  the  base,  the  leaf  becomes  oblong,  oval,  or  ovate, 
&c.  (Fig.  243).  In  one  class  of  nerved  or  parallel-veined  leaves,  the 
simple  veins  or  nerves  arise  from  a  prolongation  of  the  petiole  in  the 
form  of  a  thickened  midrib,  instead  of  the  base  of  the  blade,  constitut- 
ing the  curvinerved  leaves  of  De  Candolle.  This  structure  is  almost 
universal  in  the  Ginger  tribe,  the  Arrowroot  tribe,  in  the  Banana,  and 
other  tropical  plants ;  and  our  common  Pontederia,  or  Pickerel-weed 
(Fig.  236),  affords  an  illustration  of  it,  in  which  the  nerves  are 
curved  backwards  at  the  base,  so  as  to  produce  a  cordate  outline. 

281.  As  to  the  margin  and  particular  outline  of  leaves,  they  ex- 
hibit every  gradation  between  the  case  where  the  blade  is  entire, 
that  is,  with  the  margin  perfectly  continuous  and  even  (as  in  Fig. 
243),  and  those  where  it  is  cleft  or  divided  into  separate  portions. 
The  convenient  hypothesis  of  De  Candolle  connects  these  forms 
with  the  abundance  or  scantiness  of  the  parenchyma,  compared 
with  the  divergence  and  the  extent  of  the  ribs  or  veins ;  on  the 
supposition  that,  where  the  former  is  insufficient  completely  to  fill 
up  the  framework,  lobes,  incisions,  or  toothings  are  necessarily 
produced,  extending  from  the  margin  towards  the  centre.  Thus, 
in  the  white  and  the  yellow  species  of  Water  Ranunculus,  there 
appears  to  be  barely  sufficient  parenchyma  to  form  a  thin  covering 
for  each  vein  and  its  branches  (Fig.  251,  the  lowest  leaf)  ;  such 
leaves  are  said  to  be  Jiliformhj  dissected,  that  is,  cut  into  threads  ; 
the  nomenclature  in  all  these  cases  being  founded  on  the  conven- 
ient (but  incorrect)  supposition,  that  a  leaf  originally  entire  is  cut 
into  teeth,  lobes,  divisions,  &c.  If,  while  the  framework  remains 
the  same  as  in  the  last  instance,  the  parenchyma  be  more  abun- 


THEIR    FORMS. 


159 


dantly  developed,  as  in  fact  happens  in  the  upper  leaves  of  the  same 
species  when  they  grow  out  of  water,  and  is  shown  in  the  same 
figure,  they  are  merely  cleft  or  lobed.  If  these  lobes  grow  together 
nearly  to  the  ex- 
tremity of  the 
principal  veins, 
the  leaf  is  only 
toothed,  serrated, 
or  crenated;  and 
if  the  small  re- 
maining notches 
were  filled  with 
parenchyma,  the 
leaf  would  be  en- 
tire.    The  study 

of  the  development  of  leaves,  however,  proves  that  the  parenchyma 
grows  and  shapes  the  outlines  of  the  organ  in  its  own  Avay,  irrespec- 
tive of  the  framework,  which  is,  in  fact,  adapted  to  the  parenchyma 
rather  than  the  parenchyma  to  it.  The  principal  terms  which  designate 
the  mode  and  degree  of  division  in  simple  leaves  may  now  be  briefly 
explained,  without  further  reference  to  this  or  any  other  theory. 

282.  A  leaf  is  said  to  be  serrate,  when  the  margin  is  beset  with 
sharp  teeth  which  point  forwards  towards  the  apex  (Fig.  254)  ; 
dentate,  or  toothed,  when  the  sharp  salient  teeth  are  not  directed 
towards  the  apex  of  the  leaf  (Fig.  255)  ;  and  crenate,  when  the 
teeth  are  rounded  (Fig.  248,  25 G).  A  slightly  waved  or  sinuous 
margin  is  said  to  be  repand  (Fig.  257)  ;  a  more  strongly  uneven 
margin,  with  alternate  rounded  concavities  and  convexities,  is  termed 
sinuate  (Fig.  258).  When  the  leaf  is  irregularly  and  sharply  cut 
deep  into  the  blade,  it  is  said  to  be  incised  (Fig.  259)  ;  when  the 
portions  (or  segments)  are  more  definite,  it  is  said  to  be  lobed  (Fig. 
260,  264)  ;  and  the  terms  two-lobed,  three-lobed  (Fig.  2Qi),five-lobecl, 
&c,  express  the  number  of  the  segments.  If  the  incisions  extend  about 
to  the  middle  of  the  blade,  or  somewhat  deeper,  and  especially  if  the 
sinuses  are  acute,  the  leaf  is  said  to  be  cleft  (Fig.  261,  265)  ;  and 
the  terms  two-cleft,  three-cleft  (Fig.  265),  &c.  (or  in  the  Latin  form, 
bifid,  trifid,  &c.),  designate  the  number  of  the  segments  :  or  when 
the  latter  are  numerous  or  indefinite,  the  leaf  is  termed  many-cleft, 
or  multifid.     If  the   segments   extend  nearly,  but  not  quite,  to  the 

FIG.  254-259.     Forms  of  leaves  as  to  the  toothing  of  their  margins. 


160 


THE    LEAVES. 


base  of  the  blade  or  the  midrib,  the  leaf  is  said  to  be  parted  (Fig. 
262,    266)  :  if  they  reach  the  midrib  or  the  base,  so  as  to  interrupt 


the  parenchyma,  the  leaf  is  said  to  be  divided  (Fig.  263,  267)  ;  the 
number  of  partitions  or  divisions  being  designated,  as  before,  by  the 
terms  two-,  three-,  Jive-parted,  or  two-,  three-,  jive-divided,  &c. 

283.  As  the  mode  of  division  always  coincides  with  the  arrange- 
ment of  the  primary  veins,  the  lobes  or  incisions  of  feather-veined, 
are  differently  arranged  from  those  of  radiated  or  palmately  veined 
leaves :  in  the  latter,  the  principal  incisions  are  all  directed  to  the 
base  of  the  leaf;  in  the  former,  towards  the  midrib.  These  modi- 
fications are  accurately  described  by  tenns  indicative  of  the  vena- 
tion, combined  with  those  that  express  the  degree  of  division. 
Thus,  a  feather-viened  (in  the  Latin  form,  a  pinnately  veined)  leaf 
is  said  to  be  pinnately  cleft  or  pinnatifid  (Fig.  261),  when  the 
sinuses  reach  half-way  to  the  midrib ;  pinnately  parted,  when  they 
extend  almost  to  the  midrib  (Fig.  262)  ;  and  pinnately  divided, 
when  they  reach  the  midrib,  dividing  the  parenchyma  into  separate 
portions  (Fig.  263).  A  few  subordinate  modifications  are  in- 
dicated by  special  terms  :  thus,  a  pinnatifid  or  pinnately  parted 
leaf,  with  regular,  very  close  and  narrow  divisions,  like  the  teeth  of 
a  comb,  is  said  to  be  pectinate  ;  a  feather-veined  leaf,  more  or  less 
pinnatifid,  but  with  the  lobes  decreasing  in  size  towards  the  base,  is 

FIG.  260-267.     Pinnately  and  palmately  lobed,  cleft,  parted,  and  divided  leaves. 


THEIR    FORMS. 


161 


termed  lyrate,  or  lyre-shaped  (Fig.  278)  ;  and  a  lyrate  leaf  with 
sharp  lobes  pointing  towards  the  base,  as  in  the  Dandelion  (Fig. 
279),  is  called  runcinate.  A  pahnately  veined  leaf  is  in  like  man- 
ner said  to  he  pahnately  lobed  (Fig.  2G4),  pahnately  cleft  (Fig.  265), 
pahnately  parted  (Fig.  266),  or  'pahnately  divided  (Fig.  267),  ac- 
cording to  the  degree  of  division.  The  term  palmate  was  originally 
employed  to  designate  a  leaf  more  or  less  deeply  cut  into  about  five 
spreading  lobes,  bearing  some  resemblance  to  a  hand  with  the  fingers 
spreading ;  and  it  is  still  used  to  designate  a  pahnately  lobed  leaf, 
without  reference  to  the  depth  of  the  sinuses.  A  palmate  leaf  Avith 
the  lateral  lobes  cleft  into  two  or  more  segments  is  said  to  be  pedate 
(Fig.  249),  from  a  fancied  resemblance  to  a  bird's  foot.  By  desig- 
nating the  number  of  the  lobes  in  connection  with  the  terms  which 
indicate  their  extent  and  their  disposition,  botanists  are  enabled  to 
describe  all  these  modifications  with  great  brevity  and  precision. 
Thus,  a  pahnately  three-parted  leaf  is  one  of  the  radiated- veined  kind, 
which  is  divided  almost  to  the  base  into  three  segments  (Fig.  266)  ; 
a  pi nnately  jive-parted  leaf  is  one  of  the  feather-veined  kind  cut  into 
five  lobes  (two  on  each  side,  and  one  terminal),  with  the  sinuses  ex- 
tending almost  to  the  midrib  :  and  the  same  plan  is  followed  in  de- 
scribing cleft,  lobed,  or  divided  leaves. 

284.  The  segments  of  a  lobed  or  divided  leaf  may  be  again  di- 
vided, lobed,  or  cleft,  in  the  same  way  as  the  original  blade,  and  the 
same  terms  are  employed  in  describing  them.  Sometimes  both  the 
primary,  secondary,  and  even  tertiary  divisions  are  defined  by  a 
single  word  or  phrase ;  as  bipinnatijid  (Fig.  280),  tripinnatijid, 
bip innately  parted,  tripinnately  parted,  twice  pahnately  parted,  &c. 

285.  Parallel-veined  or  nerved  leaves  would  naturally  be  ex- 
pected to  present  entire  margins,  and  this  they  almost  universally 
do  when  the  nerves  are  convergent  (Fig.  230,  243).  Such  leaves 
are  often  lobed  or  cleft  when  the  principal  nerves  diverge  greatly, 
as  in  the  Dragon  Arum ;  but  the  lobes  themselves  are  entire. 


286.  There  are  a  few  terms  employed  in  describing  the  apex  of 
a  leaf,  which  may  be  here  enumerated.     When  a  leaf  tapers  to  a 


FIG.  268-276.    Forms  of  the  apex  of  leaves. 

14* 


162 


THE    LEAVES. 


narrowed  or  slender  apex,  it  is  said  to  be  acuminate  (Fig.  268)  : 
when  it  terminates  in  an  acute  angle,  it  is  said  to  be  acute  (Fig. 
269)  :  when  the  apex  is  an  obtuse  angle,  or  rounded,  it  is  termed 
obtuse  (Fig.  270)  :  an  obtuse  leaf,  with  the  apex  slightly  indented  or 
depi'essed  in  the  middle,  is  said  to  be  retuse  (Fig.  272),  or,  if  more 
strongly  notched,  ernarginate  (Fig.  273)  :  an  obovate  leaf  with  a 
wider  and  more  conspicuous  notch  at  the  apex  is  termed  obcordate 
(Fig.  274),  being  a  cordate  or  heart-shaped  leaf  inverted.  When 
the  apex  is,  as  it  were,  cut  off  by  a  straight  transverse  line,  the  leaf 
is  said  to  be  truncate  (Fig.  271)  :  when  abruptly  terminated  by  a 
small  and  slender  projecting  point,  it  is  mucronate  (Fig.  276)  :  when 
tipped  with  a  stronger  and  rigid  projecting  point,  or  cusp,  it  is  cuspi- 
date (Fig.  275). 

287.  All  these  terms  are  equally  applicable  to  expanded  sur- 
faces of  every  kind,  such  as  petals,  sepals,  &c. :  and  those  terms 
which  are  used  to  describe  the  modifications  of  solid  bodies,  such  as 
stems  and  stalks,  are  equally  applicable  to  leaves  when  these  affect 
similar  shapes,  as  they  sometimes  do. 

288.  The  whole  account,  thus  far,  relates  to  Simple  Leaves, 
namely,  to  those  which  have  a  blade  of  one  piece,  however  cleft  or 
lobed,  or,  if  divided,  where  the  separate  portions  are  neither  raised  on 


235  £86 


FIG   277-287.     Various  forms  of  lobed  and  compound  leaves. 


COMPOUND    LEAVES. 


163 


stalklets  of  their  own,  nor  articulated  (by  a  joint)  Avith  the  main 
petiole,  so  that  the  pieces  are  at  length  detached  and  fall  separately. 
The  distinction,  however,  cannot  he  very  strictly  maintained  ;  there 
are  so  many  transitions  between  simple  and 

289.  Compound  Leaves.  These  have  the  blade  divided  into  entire- 
ly separate  pieces ;  or,  rather,  they  consist  of  a  number  of  blades, 
borne  on  a  common  petiole,  usually  supported  on  stalklets  of  their 
own,  between  which  and  the  main  petiole  an  articulation  or  joint  is 
formed,  more  or  less  distinctly.  These  separate  blades  are  called 
Leaflets  :  they  present  all  the  diversities  of  form,  outline,  or 
division  which  simple  leaves  exhibit ;  and  the  same  terms  are  em- 
ployed in  characterizing  them.  Having  the  same  nature  and  origin 
as  the  lobes  or  segments  of  simple  leaves,  they  are  arranged  in  the 
same  ways  on  the  common  petiole.  Compound  leaves  accordingly 
occur  under  two  general  forms,  the  pinnate  and  the  palmate  (other- 
wise called  digitate). 

290.  The  pinnate  form  is  produced  when  a  leaf  of  the  pinnately 
veined  sort  becomes  compound  ;  that  is,  the  leaflets  are  situated 
along  the  sides  of  the  common  petiole.  There  are  several  modifica- 
tions of  the  pinnate  leaf.  It  is  abruptly  pinnate,  when  the  leaflets 
are  even  in  number,  and  none  is  borne  on  the  very  apex  of  the 
petiole  or  its  branches,  as  in  Cassia  (Fig.  290),  and  also  in  the 
Vetch  tribe,  where,  however,  the  apex  of  the  petiole  is  generally 


prolonged  into  a  tendril  (Fig.  287,  289).     It  is  impari-pinnate,  or 
pinnate  with  an  odd  leaflet,  when  the  petiole  is  terminated  with  a 

FIG.  288  -  290.     Simply  pinnate  leaves  of  various  forms. 


164  THE    LEAVES. 

leaflet  (Fig.  281,  288).  There  are  some  subordinate  modifications ; 
sucli  as  lyrately  pinnate,  when  the  blade  of  a  lyrate  leaf  (Fig.  278) 
is  completely  divided,  as  in  Fig.  285  ;  and  interruptedly  pinnate, 
when  some  minute  leaflets  are  irregularly  intermixed  with  larger 
ones,  as  is  also  shown  to  some  extent  in  the  figure  last  cited.  The 
number  of  leaflets  varies  from  a  great  number  to  very  few.  When 
reduced  to  a  small  number,  such  a  leaf  is  said  to  be  pinnately  seven-, 
or  jive-,  or  tri-foliolate,  as  the  case  may  be.  A  pinnate  leaf  of  three 
or  five  leaflets  is  often  called  ternate  or  quinate  ;  which  terms,  how- 
ever, are  equally  applied  to  a  palmately  compound  leaf,  and  also, 
and  more  appropriately,  to  the  case  of  three  or  five  simple  leaves 
growing  on  the  same  node.  A  pinnately  trifoliolate  leaf  (Fig.  286) 
is  readily  distinguished  by  having  the  two  lateral  leaflets  attached 
to  the  petiole  at  some  distance  below  its  apex,  and  by  the  joint 
which  is  observable  at  some  point  between  their  insertion  and  the 
lamina  of  the  terminal  leaflet.  Such  a  leaf  may  even  be  reduced 
to  a  single  leaflet ;  as  in  the  Orange  (Fig.  283)  and  the  primordial 
leaves  of  the  common  Barberry.  This  is  distinguished  from  a 
really  simple  leaf  by  the  joint  at  the  junction  of  the  partial  with  the 
general  petiole. 

291.  The  palmate  or  digitate  form  is  produced  when  a  leaf  of  the 
palmately  veined  sort  becomes  compound  ;  in  which  case  the  leaflets 
are  necessarily  all  attached  to  the  apex  of  the  common  petiole,  as  in 
the  Horsechestnut  and  Buckeye  (Fig.  277),  and  the  common  Clover 
(Fig.  304).  Such  leaves  of  three,  five,  or  any  definite  number  of 
leaflets,  are  termed  palmately  (or  digitately)  trifoliolate,  five-foliolate, 
&c.  A  leaf  of  two  leaflets,  which  rarely  occurs,  is  unijugate  (one- 
paired)  or  binate.  By  this  nomenclature,  the  distinction  between 
pinnately  and  palmately  compound  leaves  is  readily  kept  up,  and 
every  important  character  of  a  leaf  is  expressed  with  brevity  and 
accuracy. 

292.  The  stalk  of  a  leaflet  is  called  a  partial  petiole  (petiolule)  ; 
and  the  leaflet  thus  supported  is  petiolulate.  The  partial  petioles 
may  bear  a  set  of  leaflets,  instead  of  a  single  one,  when  the  leaf 
becomes  doubly  or  twice  compound.  Thus  a  pinnate  leaf  again  com- 
pounded in  the  same  way  becomes  bipinnate  (Fig.  282),  or  if  still 
a  third  time  divided  it  is  tripinnate,  &c.  In  these  cases  the  main 
divisions  or  branches  of  the  common  petiole  are  called  pinnae,  or  the 
pairs  jugce.  So  a  trifoliolate  leaf  twice  compound  becomes  biternate 
(Fig.  284)  ;  or  thrice,  tritemate,  &c.     When  the  primary  division 


VERTICAL  AND  PERFOLIATE  LEAVES. 


165 


is  digitate,  the  secondary  division  is  often  pinnate,  thus  combining 
the  two  modes  in  the  same  leaf.  A  leaf  irregularly  or  indeter- 
minately several  times  compounded,  in  whatever  mode,  is  said  to  be 
decompound. 

293.  Leaves  of  Peculiar  Conformation.    The  blade  of  a  leaf  is  almost 

always  symmetrical,  that  is,  the  portions  on  each  side  of  the  midrib 
or  axis  are  similar ;  but  occasionally  one  side  is  more  developed  than 
the  other,  when  the  leaf  is  oblique,  as  is  strikingly  the  case  in  the 
species  of  Begonia  (Fig.  246)  of  our  conservatories. 

294.  Vertical  and  Equitant  Leaves.  The  blade  is  also 

commonly  horizontal,  presenting  one  surface  to  the 
sky,  and  the  other  to  the  earth  ;  in  which  case  the 
two  surfaces  differ  in  structure  (262)  as  well  as  in 
appearance,  each  being  fitted  for  its  peculiar  of- 
fices :  if  artificially  reversed,  they  spontaneously 
resume  their  natural  position,  or  soon  perish  if 
prevented  from  doing  so.  But  in  erect  and  verti- 
cal leaves,  the  two  surfaces  are  equally  exposed 
to  the  light,  and  are  similar  in  structure  and  ap- 
pearance. In  such  erect  and  equitant  leaves  as 
those  of  Iris  (Fig.  291),  it  is  really  the  lower  sur- 
face that  is  presented  to  the  air ;  for  the  leaf  is 
folded  together  lengthwise 
(con-duplicate),  and  consoli- 
dated while  in  the  nascent 
state,  so  that  the  true  upper 
surface  is  concealed  in  the 
interior,  except  near  the 
base,  where  they  alternately 
cover  over  each  other  in  the 
equitant  manner  (258,  Fig. 
292).  True  vertical  leaves, 
which  present  their  edges  instead  of  their  surfaces  to  the  earth  and 
sky,  generally  assume  this  position  by  a  twisting  of  the  base  or 
the  petiole  ;  as  is  strikingly  seen  in  the  Callistemon  and  many  other 
Australian  trees  of  the  Myrtle  family,  some  of  which  are  now  com- 
mon in  green-houses. 

295.  Perfoliate  Leaves.      While    in    Iris  the    two    halves    of  the 


FIG.  291.     Equitant  erect  leaves  of  Iris,  with  the  rootstock. 

FIG.  292.     A  section  across  these  leaves  at  the  base,  showiDg  their  equitant  character. 


166 


THE    LEAVES, 


upper  surface  of  a  folded  leaf  cohere,  those  of  some  other  plants  ex- 
hibit a  cohesion  by  their  contiguous  edges,  and  give  rise  to  a  differ- 
ent anomaly.  This  is  illustrated  by  peltate 
leaves  (Fig.  248),  and  more  strikingly  by 
what  are  termed  perfoliate  leaves.  These  in 
some  cases  originate  from  the  union  of  the 
bases  of  a  pair  of  opposite  sessile  leaves  (con- 
nate^perfoliate),  as  in  Silphium  perfoliatum, 
Triosteum  perfo- 
liatum, and  the 
upper  pairs  of 
true  Honeysuckle 
(Fig.  294).  In 
others  they  con- 
sist of  a  single 
clasping  leaf,  the 
posterior  lobes  of 
which  encompass  the  stem  and  cohere 
on  the  opposite  side,  as  is  seen  in  Bu- 
pleurum  rotundifolium,  Uvularia  perfo- 
liata,  and  Baptisia  perfoliata  (Fig.  293). 

296.  Leaves  with  no  distinction  of  Blade 

and  Petiole.  The  leaves  of  the  Iris,  as 
well  as  those  of  the  Daffodil,  the  Onion, 
and  of  many  other  Endogens,  show  no 

distinction  of  blade  and  petiole.  In  some  the  leaf  of  this  sort  may 
be  regarded  as  a  sessile  blade ;  in  others,  rather  as  a  petiole  per- 
forming the  functions  of  a  blade.  Leaves  are  not  always  expanded 
bodies.  Sometimes  they  are  filiform  or  thread-shaped,  as  those  of 
Asparagus  :  some  are  acicular,  acerose,  or  needle-shaped,  as  in  Pines 
and  Larches  (Fig.  212,  213)  ;  others  are  subulate  or  awl-shaped,  as 
in  Juniper,  &c.  The  Red  Cedar  and  Arbor  Vitas  (Fig.  295)  exhibit 
both  awl-shaped  and  scale-shaped  leaves  on  different  branchlets. 

297.  Succulent  or  Fleshy  Leaves,  like  those  of  Stonecrop,  House- 
leek,  Mesembryanthemum  or  Ice-Plant,  and  the  Agave  or  Century- 
Plant,  usually  assume  shapes  more  or  less  unlike  ordinary  foliage. 
Some  of  them  are  terete,  like  stems,  or  at  least  have  no  distinct 
upper  and  lower  surface.     These  greatly  thickened  leaves  serve  a 


FIG.  293.     Perfoliate  (single)  leaves  of  Baptisia  perfoliata. 

FIG.  294.     Connate-perfoliate  leaves  of  a  wild  Honeysuckle  (Lonicera  flava). 


AS    BUD-SCALES,    TENDRILS,    SPINES,    ETC. 


167 


double  purpose,  being  not  only  organs  for  assimilation,  —  the  general 
office  of  foliage,  —  but  also  repositories  in  which 
assimilated  matter  is  stored  up,  just  as  in  the  root 
of  the  Beet  and  Radish  (Fig.  138),  or  in  subter- 
ranean stems  or  branches  in  rootstocks,  tubers, 
and  corms  ( 188  - 190, 194).  The  bases  of  those 
leaves  which  form  the  scales  of  bulbs  (191)  are 
turned  to  the  same  use.  In  Fig.  176  we  have  a 
leaf  the  blade  of  which  acts  as  foliage  in  the  ordi- 
nary manner  of  leaves,  while  its  subterranean 
thickened  base  serves  as  a  repository  of  nutri- 
ment which  the  blade  has  elaborated.  The  very 
first  leaves  of  the  plant,  viz.  the  cotyledons  or 
seed-leaves  (120  — 123)  are  commonly  subservi- 
ent to  this  purpose,  and  some- 
times to  no  other,  as  in  the 
Pea,  Horsechestnut,  Oak,  &c. 
(124),  where  these  leaves  are  mere  repositories 
of  food  for  the  use  of  the  germinating  plant. 

'298.  Leaves  as  Bud-scales,  &c.  (161)  exhibit  the 

same  organ  under  a  different  modification,  and 
subserving  a  different  special  purpose.  Of  the 
same  nature  are  the  degenerated  or  abortive 
scale-like  leaves  on  the  vernal  stems  of  peren- 
nial herbs  near  or  beneath  the  surface  of  the 
ground,  and  on  Asparagus  shoots,  and  also  those 
scales  which  colored  parasitic  plants  produce  in 
place  of  foliage  (152).  The  primary  leaves  of 
Pines  are  all  thin  and  dry  bud-scales  ;  the  actual 
foliage  originating  from  a  branch  in  the  axil  of 
each  (Fig.  212). 

299.  Leaves  as  Tendrils  are  seen  in  the  proper 

Pea  tribe  ;  where  however  only  the  extremity 

of  the   common  petiole  is  transformed  in  this 

manner    (Fig.   287,    289) ;   but   in   one   plant 

of  the  kind  (Lathyrus  Aphaca)  the  whole  leaf  becomes  a  tendril. 

300.  Leaves  as  Spines  occur  in  several  plants.     The  primary  leaves 

FIG.  295.  A  twig  of  American  Arbor  Vitse,  exhibiting  both  awl-shaped  and  scale-shaped 
leaves. 

FIG.  296.  A  summer  shoot  of  the  Barberry,  showing  a  lower  leaf  in  the  normal  state  ;  the 
next  partially,  those  still  higher  completely,  transformed  into  spines. 


168 


THE    LEAVES, 


of  the  shoots  of  the  common  Barberry  offer  a  familiar  instance  of 
the  kind  (Fig.  29G).  The  most  extraordinary  modification  of  the 
leaf  occurs  in  the 

301.  Fly-traps  of  Dionrea  muscipula,  the  Venus's  Fly-trap  of  North 

Carolina  (which  is  found  only 
in  the  vicinity  of  Wilming- 
ton, where  it  abounds  in 
wet  and  sandy  bogs).     Each 


i 


leaf  of  this  most  curious  plant  bears  at  its  summit  an  append- 
age (answering,  perhaps,  to  the  proper  blade),  which  opens  and 
shuts :  fringed  with  strong  bristles  or  slender  teeth  on  its  margin, 
it  bears  some  resemblance  to  a  steel-trap,  and  operates  much  like 
one.  For  when  open,  as  it  commonly  is  when  the  sun  shines, 
no  sooner  does  a  fly  alight  on  its  surface,  and  brush  against  any 
one  of  the  several  long  bristles  that  grow  there,  than  the  trap 
suddenly  closes,  often  capturing  the  intruder,  pressing  it  all  the 
harder  for  its  struggles,  and  commonly  depriving  it  of  life.  After 
all  movement  has  ceased  within,  the  trap  slowly  opens,  and  is  ready 
for  another  capture.  Why  this  plant  catches  insects,  we  are  unable 
to  say ;  and  as  to  the  mechanism  of  the  movement  it  is  no  more  and 
no  less  explicable  than  the  much  slower  movements  of  ordinary 
leaves  in  changing  their  position. 


FIG.  297.     A  plant  of  Dionaea  muscipula,  reduced  in  size.    298.  Three  of  the  leaves,  of 
nearly  the  natural  size  ;  one  of  them  open,  the  others  closed. 


AS   ASCIDIA    OR   PITCHERS. 


169 


302.  Ascidia  or  Pitchers,  or  tubes  open  at  the  summit,  represent 
another  remarkable  form  of  leaves.  These  occur  in  several  plants 
of  widely  different  families.  If  we  conceive  the  margins  of  the 
dilated  part  of  the  leaf  of  Dionasa  to  curve  inwards  until  they  meet, 
and  cohere  with  each  other,  there  would  result  a  leaf  in  form  not 
unlike  that  of  Sarracenia  purpurea,  the  common  Pitcher-plant  or 
Sidesaddle  Flower  of  the  Northern  United  States  (Fig.  300).     So 


the  tube  or  pitcher  has  been  supposed  to  answer  to  the  petiole,  and 
the  hood  at  the  summit  to  the  blade.  And  this  view  is  strengthened 
by  a  Pitcher-plant  of  the  same  family  (Heliamphora,  Fig.  299), 
discovered  by  Mr.  Schomburgk  in  the  mountains  of  British  Guiana, 
in  which  the  pitcher  is  not  always  completed  quite  to  the  summit, 
and  the  hood  is  represented  by  a  small  concave  terminal  appendage. 
In  the  curious  Nepenthes  (Fig.  301),  the  petiole  is  first  dilated  into 
a  kind  of  lamina,  then  contracted  into  a  tendril,  and  finally  dilated 
into  a  pitcher,  containing  fluid  secreted  by  the  plant  itself;  the  orifice 
being  accurately  closed  by  a  lid,  which  from  analogy  was  supposed  to 
represent  the  real  blade  of  the  leaf.  The  study  of  the  development, 
however  (recently  made  by  Dr.  Hooker),  does  not  confirm  this 
hypothesis.  The  whole  pitcher  of  Nepenthes  is  only  an  anom- 
alous appendage  of  the  tendril-like  prolongation  of  the  midrib  of  the 
real  blade  of  the  leaf.  A  new  Pitcher-plant  of  the  Sarracenia  family 
(the  Darlingtonia),  discovered  by  Mr.  Brackenridge  in  California, 

FIG.  299.  Pitchers  of  Heliamphora ;  300,  of  Sarracenia  purpurea ;  301,  of  Nepenthes. 
302.  A  phyllodiuin  of  a  New  Holland  Acacia.  303.  The  same,  bearing  a  reduced  compound 
blade. 

15 


170  THE    LEAVES. 

has  recently  been  made  known  by  Dr.  Torrey.  In  this  the  enlarged 
summit  of  the  tube  is  strongly  arched  like  a  hood  (as  in  Sarracenia 
psittacina  of  the  Southern  States),  and  is  abruptly  terminated  by  a 
singular  two-lobed  foliaceous  appendage,  resembling  the  forked  tail 
of  a  fish. 

303.  TllC  Petiole,  or  Leafstalk,  is  usually  either  round,  or  half-cylin- 
drical and  channelled  on  the  upper  side.  But  in  the  Aspen,  it  is 
strongly  flattened  at  right  angles  with  the  blade,  so  that  the  slightest 
breath  of  air  puts  the  leaves  in  motion.  It  is  not  unfrequently  fur- 
nished with  a  leaf-like  border,  or  ring  ;  which,  in  the  Sweet  Pea  of 
the  gardens,  extends  downward  along  the  stem,  on  which  the  leaves 
are  then  said  to  be  decurrent ;  or  the  stalk  or  stem  thus  bordered 
is  said  to  be  alate  or  winged.  In  many  Umbelliferous  plants,  the 
petiole  is  dilated  below  into  a  broad  and  membranaceous  inflated 
sheath ;  and  in  a  great  number  of  Endogenous  plants  the  petiole 
consists  of  a  sheath,  embracing  the  stem,  which  in  Grasses  is  fur- 
nished at  the  summit  with  a  membranous  appendage,  in  some  sort 
equivalent  to  the  stipules,  called  the  ligide  (Fig.  237).  The  woody 
and  vascular  tissue  runs  lengthwise  through  the  petiole,  in  the  form 
usually  of  a  definite  number  of  parallel  threads,  to  be  ramified  in  the 
blade.  The  ends  of  these  threads  are  apparent  on  the  base  of  the 
leafstalk  when  it  falls  off,  and  on  the  scar  left  on  the  stem,  as  so 
many  round  dots  (Fig.  153,  b),  of  a  uniform  number  and  arrange- 
ment in  each  species. 

304.  Fhyllodia  (Fig.  302,  303).  Occasionally  the  whole  petiole 
dilates  into  a  kind  of  blade,  traversed  by  ribs,  mostly  of  the  parallel- 
veined  kind.  In  these  cases  the  proper  blade  of  the  leaf  commonly 
disappears  ;  this  substitute,  called  a  Phyllodium  (meaning  a  leaf-like 
body),  taking  its  place.  These  phyllodia  constitute  the  whole  foliage 
of  the  numerous  Australian  Acacias.  Here  they  are  at  once  dis- 
tinguished from  leaves  with  a  true  blade  by  being  entire  and  parallel- 
veined  ;  while  their  proper  leaves  (of  which  the  earlier  ones  uni- 
formly appear  in  germination,  and  also  later  ones  in  casual  instances) 
are  compound  and  netted-veined.  They  are  also  to  be  recognized  by 
their  uniformly  vertical  position,  presenting  their  margins  instead  of 
their  surfaces  to  the  earth  and  sky ;  and  they  sometimes  bear  a  true 
compound  lamina  at  the  apex,  as  in  Fig.  303. 

305.  Stipules  (259,  Fig.  229)  are  lateral  appendages  of  leaves, 
usually  appearing  as  small  foliaceous  bodies,  one  on  each  side  of  the 
base  of  the  petiole.     They  are  not  found  at  all  in  a  great  number  of 


STIPULES. 


171 


plants  ;  but  their  presence  or  absence  is  usually  uniform  throughout 
a  natural  order.  Stipules  assume  a  great  variety  of  forms  analogous 
to  those  of  the  blade.  Like  it  they  are  sometimes  membranaceous 
or  scale-like,  and  sometimes  transformed  into  spines,  as  in  the  Locust- 
tree,  &c.  They  are  sometimes  present  on  developing  shoots 
only ;  as  in  the  Beech,  the  Fig,  and  the  Magnolia  (Fig.  155,  15G), 
where  they  form  the  covering  of  the  buds,  but  fall  away  as  the 
leaves  expand.  They  have  a  strong 
tendency  to  cohere  with  each  other,  or 
with  the  base  of  the  petiole.  Thus,  in 
the  Clover  (Fig.  304),  the  Strawberry, 
and  the  Rose  (Fig.  281),  a  stipule  ad- 
heres to  each  side  of  the  base  of  the 
petiole  ;  in  the  Plane-tree,  the  two  are 
free  from  the  petiole,  but  cohere  by 
their  outer  margins,  so  as  to  form  an 
apparently  single  stipule  opposite  the 
leaf.  In  other  cases,  both  margins  are 
united,  forming  a  sheath  around  the 
stem,  just  above  the  leaf:  these  are 
called  intrafoliaceous  stipules ;  and 
when  membranaceous,  as  in  Polygo- 
num (Fig.  305),  they  have  been  termed 
ochrece.  When  opposite  leaves  have 
stipules,  they  usually  occupy  the  space 
between  the  petioles  on  each  side,  and 
are  termed  interpetiolar.  The  stipules 
of  each  leaf  (one  on  each  side),  being 
thus  placed  in  contact,  frequently  unite  mi 

so  as  to  form  apparently  but  a  single  pair  of  stipules  for  each  pair 
of  leaves  ;  instances  of  which  are  very  common  in  the  order 
Eubiaceae. 

306.  Leaves  furnished  with  stipules  are  said  to  be  stipulate :  when 
destitute  of  them,  exstipulate.  The  leaflets  of  compound  leaves  are 
sometimes  provided  with  small  stipules  (termed  stipelles)  of  their 
own,  as  in  the  Bean  (Fig.  286)  ;  Avhen  they  are  said  to  be  stipellate. 

FIG.  304.  A  leaf  of  Red  Clover,  with  its  three  leaflets  at  the  summit  of  the  leafstalk,  to 
which  at  the  base  the  stipules  (st)  are  adherent,  one  on  each  side. 

FIG.  305.  Part  of  a  leaf  of  Polygonum  orientale,  with  its  stipules  united  into  a  sheath 
{ochrea)  and  surrounding  the  stem. 


172  THE     LEAVES. 


Sect.  III.      The   Duration   of  Leaves,  and  the   General 
Action   of  Foliage. 

307.  Leaves  last  only  for  a  limited  period,  and  are  thrown  off, 
or  else  perish  and  decay  on  the  stem,  after  having  fulfilled  their 
office  for  a  certain  time. 

308.  Duration  Of  Leaves.  In  view  of  their  duration,  leaves  are 
called  fugacious,  when  they  fall  off  soon  after  their  appearance ; 
deciduous,  when  they  last  only  for  a  single  season  ;  and  persist- 
ent, when  they  remain  through  the  cold  season,  or  other  interval 
during  which  vegetation  is  interrupted,  and  until  after  the  appear- 
ance of  new  leaves,  so  that  the  stem  is  never  leafless ;  as  in  Ever- 
greens. 

309.  Leaves  last  only  for  a  single  year  in  many  Evergreens,  as 
well  as  in  deciduous-leaved  plants  ;  the  old  leaves  falling  soon  after 
those  of  the  ensuing  season  are  expanded,  or,  if  they  remain  longer, 
ceasing  to  bear  any  active  part  in  the  economy  of  the  vegetable, 
and  soon  losing  their  vitality  altogether.  In  Pines  and  Firs,  how- 
ever, although  there  is  an  annual  fall  of  leaves  either  in  autumn  or 
spring,  yet  these  were  the  produce  of  some  season  earlier  than  the 
last ;  and  the  branches  are  continually  clothed  with  the  foliage  of 
from  two  to  five,  or  even  eight  or  ten,  successive  years.  On  the 
other  hand,  it  is  seldom  that  all  the  leaves  of  an  herb  endure 
through  the  whole  growing  season,  the  earlier  foliage  near  the  base 
of  the  stem  perishing  while  fresh  leaves  are  still  appearing  above. 
In  our  deciduous  trees  and  shrubs,  however,  the  leaves  of  the 
season  are  mostly  developed  within  a  short  period,  and  they  all 
perish  nearly  at  the  same  time.  They  are  not  destroyed  by  frost, 
as  is  commonly  supposed ;  for  they  begin  to  languish,  and  often 
assume  their  autumnal  tints  (as  happens  with  the  Red  Maple 
especially),  or  even  fall,  before  the  earlier  frosts ;  and  when  vernal 
vegetation  is  destroyed  by  frost,  the  leaves  blacken  and  wither,  but 
do  not  fall  off  entire,  as  they  do  in  autumn.  Some  leaves  are  cast 
off,  indeed,  while  their  tissues  have  by  no  means  lost  their  vital- 
ity. Death  is  often  rather  a  consequence  than  the  cause  of  the 
fall.  Others  die  and  decay  on  the  stem  without  falling,  as  in 
Palms  and  most  Endogens.  In  some  cases  many  of  the  dead 
leaves  hang  on  the  branches  through  the  winter,  as  in  the  Beech, 
falling  only  Avhen  the  new  buds  expand,  the  following  spring.     We 


THEIR   DEATH    AND    FALL.  173 

must  therefore  distinguish  between  the  death  and  the  fall  of  the 
leaf. 

310.  The  Fall  Of  the  Leaf  is  owing  to  an  organic  separation,  through 
an  articulation,  or  joint,  which  forms  between  the  base  of  the 
petiole  and  the  surface  of  the  stem  on  which  it  rests.  The  forma- 
tion of  the  articulation  is  a  vital  process,  a  kind  of  disintegration  of 
a  transverse  layer  of  cells,  which  cuts  off  the  petiole  by  a  regular 
line,  in  a  perfectly  uniform  manner  in  each  species,  leaving  a  clean 
scar  at  the  insertion  (Fig.  153,  155).  The  solution  of  continuity 
begins  in  the  epidermis,  where  a  faint  line  marks  the  position  of  the 
future  joint  while  the  leaf  is  still  young  and  vigorous  :  later,  the 
line  of  demarcation  becomes  well  marked,  internally  as  well  as  ex- 
ternally ;  the  disintegrating  process  advances  from  without  inwards, 
until  it  reaches  the  woody  bundles ;  and  the  side  next  the  stem, 
which  is  to  form  the  surface  of  the  scar,  has  a  layer  of  cells  con- 
densed into  what  appears  like  a  prolongation  of  the  epidermis,  so 
that,  when  the  leaf  separates,  "the  tree  does  not  suffer  from  the 
effects  of  an  open  wound."  "  The  provision  for  the  separation  being 
once  complete,  it  requires  little  to  effect  it ;  a  desiccation  of  one  side 
of  the  leafstalk,  by  causing  an  effort  of  torsion,  will  readily  break 
through  the  small  remains  of  the  fibro-vascular  bundles  ;  or  the  in- 
creased size  of  the  coming  leaf-bud  will  snap  them ;  or,  if  these 
causes  are  not  in  operation,  a  gust  of  wind,  a  heavy  shower,  or  even 
the  simple  weight  of  the  lamina,  will  be  enough  to  disrupt  the  small 
connections  and  send  the  suicidal  member  to  its  grave.  Such  is  the 
history  of  the  fall  of  the  leaf.  "We  have  found  that  it  is  not  an  ac- 
cidental occurrence,  arising  simply  from  the  vicissitudes  of  tempera- 
ture and  the  like,  but  a  regular  and  vital  process,  which  commences 
with  the  first  formation  of  the  organ,  and  is  completed  only  when 
that  is  no  longer  useful ;  and  we  cannot  help  admiring  the  wonder- 
ful provision  that  heals  the  wound  even  before  it  is  absolutely  made, 
and  affords  a  covering  from  atmospheric  changes  before  the  part  can 
be  subjected  to  them."  *  Leaves  fall  by  an  articulation  in  most 
Exogenous  plants,  where  the  insertion  usually  occupies  only  a 
moderate  part  of  the  circumference  of  the  stem,  and  especially  in 
those  with  woody  stems  which  continue  to  increase  in  diameter. 
When  they  are  not  cast  off  in  autumn,  therefore,  the  disruption 
inevitably  takes  place  the  next  spring,  or  whenever  the  circumfer- 

*  Dr.  Inman,  in  Ilenfrey's  Botanical  Gazette,  Vol.  1.  p.  61. 

15* 


174  THE    LEAVES. 

ence  further  enlarges.  But  in  most  Endogenous  plants,  where  the 
leaves  are  scarcely,  if  at  all,  articulated  with  the  stem,  which  in- 
creases little  in  diameter  subsequent  to  its  early  growth,  they  are 
not  thrown  off,  but  simply  wither  and  decay ;  their  dead  bases  or 
petioles  being  often  persistent  for  a  long  time. 

311.  The  Death  of  the  Leaf,  however,  in  these  and  other  cases,  is 
still  to  be  explained.  Why  have  leaves  such  a  temporary  exist- 
ence ?  Why  in  ordinary  cases  do  they  last  only  for  a  single  year, 
or  a  single  summer  ?  An  answer  to  this  question  is  to  be  found 
in  the  anatomical  structure  of  the  leaf,  and  the  nature  and  amount 
of  the  fluid  which  it  receives  and  exhales.  The  water  continually 
absorbed  by  the  roots  dissolves,  as  it  percolates  the  soil,  a  small 
portion  of  earthy  matter.  In  limestone  districts  especially,  it  takes 
up  a  sensible  quantity  of  carbonate  and  sulphate  of  lime,  and  be- 
comes hard.  It  likewise  dissolves  a  smaller  proportion  of  silex, 
magnesia,  potash,  &c.  A  part  of  this  mineral  matter  (44,  93)  is  at 
once  deposited  in  the  woody  tissue  of  the  stem  ;  but  a  larger  por- 
tion is  carried  into  the  leaves,  where,  as  the  water  is  exhaled 
pure,  all  this  earthy  substance,  not  being  volatile,  must  be  left  be- 
hind to  incrust  the  delicate  cells  of  the  parenchyma,  much  as  the 
vessels  in  which  water  is  boiled  for  culinary  purposes  are  in  time 
incrusted  with  an  earthy  deposit.  Tins  earthy  incrustation,  in  con- 
nection with  the  deposition  of  organic  solidified  matter,  must  grad- 
ually choke  the  tissue  of  the  leaf,  and  finally  unfit  it  for  the  per- 
formance of  its  offices.  Hence  the  fresh  leaves  most  actively  fulfil 
their  functions  in  spring  and  early  summer ;  but  languish  towards 
autumn,  and  erelong  inevitably  perish.  Hence,  although  the  roots 
and  branches  may  be  permanent,  the  necessity  that  the  leaves 
should  be  annually  renewed.  But  the  former  are,  in  fact,  annually 
renewed  likewise  ;  and  life  abandons  the  annual  layers  of  wood  and 
bark  almost  as  soon  as  it  does  the  leaves  they  supply  (224,  231), 
and  for  similar  reasons ;  although  their  situation  is  such  that  they 
become  part  of  a  permanent  structure,  and  serve  to  convey  the  sap, 
even  when  no  longer  endowed  with  vitality. 

312.  The  general  correctness  of  this  view  may  be  tested  by  direct 
microscopical  observation.  In  Fig.  223,  224,  some  superficial  paren- 
chyma thus  obstructed  by  long  use  is  represented ;  and  similar 
illustrations  may  be  obtained  from  ordinary  leaves.  That  this 
deposit  consists  in  great  part  of  earthy  matter,  is  shown  by  care- 
fully burning  away  the  organic  materials  of  an  autumnal  leaf  over 


EXHALATION   AND    THE    RISE    OF   THE    SAP.  175 

a  lamp,  and  examining  the  ashes  by  the  microscope  ;  which  will  be 
found  very  perfectly  to  exhibit  the  form  of  the  cells.  The  ashes 
which  remain  when  a  leaf  or  other  vegetable  substance  is  burned 
in  the  open  air,  represent  the  earthy  materials  which  it  has  accu- 
mulated. A  vernal  leaf  leaves  only  a  small  quantity  of  ashes ;  an 
autumnal  leaf  yields  a  very  large  proportion,  —  from  ten  to  thirty 
times  as  much  as  the  wood  of  the  same  species  ;  although  the  leaves 
contain  the  deposit  of  a  single  season  only,  while  the  heart-wood  is 
loaded  with  the  accumulations  of  successive  years.* 

313.  Exhalation  from  the  Leaves.  The  quantity  of  water  exhaled 
from  the  leaves  during  active  vegetation  is  very  great.  In  one  of 
the  well-known  experiments  of  Hales,  a  Sunflower  tliree  and  a  half 
feet  high,  with  a  surface  of  5,616  square  inches  exposed  to  the  air, 
was  found  to  perspire  at  the  rate  of  twenty  to  thirty  ounces  avoirdu- 
pois every  twelve  hours,  or  seventeen  times  more  than  a  man.  A 
Vine,  with  twelve  square  feet  of  foliage,  exhaled  at  the  rate  of  five 
or  six  ounces  a  day  ;  and  a  seedling  Apple-tree,  with  eleven  square 
feet  of  foliage,  lost  nine  ounces  a  day.  The  amount  varies  with  the 
degree  of  warmth  and  dryness  of  the  air,  and  of  exposure  to  light ; 
and  is  also  very  different  in  different  species,  some  exhaling  more 
copiously  even  than  the  Sunflower.  But  when  we  consider  the  vast 
perspiring  surface  presented  by  a  large  tree  in  full  leaf,  it  is  evident 
that  the  quantity  of  watery  vapor  it  exhales  must  be  immense. 
This  exhalation  is  dependent  on  the  capacity  of  the  air  for  moisture 
at  the  time,  and  upon  the  presence  of  the  sun ;  often  it  is  scarcely 
perceptible  during  the  night.  The  Sunflower,  in  the  experiment  of 
Hales,  lost  only  three  ounces  in  a  warm,  dry  night,  and  underwent 
no  diminution  during  a  dewy  night. 

314.  Rise  of  the  Sap.  Now  this  exhalation  by  the  leaves  requires 
a  corresponding  absorption  by  the  roots.  The  one  is  the  measure 
of  the  other.  If  the  leaves  exhale  more  in  a  given  time  than  the 
roots  can  restore  by  absorption  from  the  soil,  the  foliage  droops  ; 
as  we  see  in  a  hot  and  dry  summer  afternoon,  when  the  drain  by 

*  The  dried  leaves  of  the  Elm  contain  more  than  eleven  per  cent  of  ashes, 
while  the  wood  contains  less  than  two  per  cent ;  those  of  the  Willow,  more 
than  eight  per  cent,  while  the  wood  has  only  0.45 ;  those  of  the  Beech,  6.6$, 
the  wood  only  0.36  ;  those  of  the  (European)  Oak,  4.05,  the  wood  only  0.21  ; 
those  of  the  Pitch-Pine,  3.15,  the  wood  only  0.25  per  cent.  Hence  the  decaying 
foliage  in  our  forests  restores  to  the  soil  a  large  proportion  of  the  inorganic 
matter  which  the  trees  from  year  to  year  take  from  it. 


176  THE    LEAVES. 

exhalation  is  very  great,  while  a  further  supply  of  moisture  can 
hardly  be  extorted  from  the  parched  soil ;  —  as  we  observe  also  in 
a  leafy  plant  newly  transplanted,  where  the  injured  rootlets  are  not 
immediately  in  a  fit  condition  for  absorption.  Ordinarily,  how- 
ever, exhalation  by  the  leaves  and  absorption  by  the  roots  are  in 
direct  ratio  to  each  other,  and  the  loss  sustained  by  the  leaves  is 
immediately  restored  (by  endosmosis,  40)  through  the  ascent  of  the 
sap  from  the  branches,  the  latter  being  constantly  supplied  by  the 
stem ;  so  that,  during  active  vegetation,  the  sap  ascends  from  the 
remotest  rootlets  to  the  highest  leaves,  at  a  rate  corresponding  to 
the  amount  of  exhalation.  The  action  of  the  leaves  is,  therefore, 
the  principal  mechanical  cause  of  the  ascent  of  the  sap.  This  is 
well  illustrated  when  a  graft  has  a  different  time  of  leafing  from 
that  of  the  stock  upon  which  it  is  made  to  grow,  the  graft  wholly 
regulating  the  season  or  temperature  at  which  the  sap  is  put  in 
motion,  and  controlling  the  habits  of  the  original  stock.  Also  by 
introducing  the  branches  of  a  tree  into  a  conservatory  during 
winter ;  when,  as  their  buds  expand,  the  sap  in  the  trunk  without 
is  set  unseasonably  into  motion  to  supply  the  demand. 

315.  During  the  summer's  vegetation,  Avhile  the  sap  is  consumed 
or  exhaled  almost  as  fast  as  it  enters  the  plant,  no  considerable  ac- 
cumulation can  take  place :  but  in  autumn,  when  the  leaves  perish, 
the  rootlets,  buried  in  the  soil  beyond  the  influence  of  the  cold, 
Avhich  checks  all  vegetation  above  ground,  continue  for  a  time  slowly 
to  absorb  the  fluid  presented  to  them.  Thus  the  trunks  of  many 
trees  are  at  this  season  gorged  with  sap,  which  will  flow  from  in- 
cisions made  into  the  wood.  This  sap  undergoes  a  gradual  change 
during  the  winter,  and  deposits  its  solid  matter  in  the  cells  of  the 
wood.  The  absorption  recommences  in  the  spring,  before  new 
leaves  are  expanded  to  consume  the  fluid ;  chemical  changes  take 
place  ;  the  soluble  matters  in  the  tissue  of  the  stem  are  redissolved, 
and  the  trunk  is  consequently  again  gorged  with  sap,  which  will 
flow,  or  bleed,  when  wounded.  But  when  the  leaves  resume  their 
functions,  or  when  flowers  are  developed  before  the  leaves  appear, 
as  in  many  forest-trees,  this  stock  of  rich  sap  is  rapidly  consumed, 
and  the  sap  will  no  longer  flow  from  an  incision.  It  is  not,  there- 
fore, at  the  period  when  the  trunk  is  most  gorged  with  sap,  in  spring 
and  autumn,  but  when  least  so,  during  summer,  that  the  sap  is  prob- 
ably most  rapidly  ascending. 


PHYSIOLOGY    OF    VEGETATION.  177 

CHAPTER     VI. 

OF   THE   FOOD    AND    NUTRITION    OF   PLANTS. 
Sect.  I.     The  General  Physiology  of  Vegetation. 

316.  The  Organs  of  Vegetation  or  Nutrition  (those  by  which 
plants  grow  and  form  their  various  products)  having  now  been  con- 
sidered, both  as  to  their  structure  and  to  some  extent  as  to  their 
action,  Ave  are  prepared  to  take  a  comprehensive  survey  of  the 
general  results  of  vegetation ;  to  inquire  into  the  elementary  com- 
position of  plants,  the  nature  of  the  food  by  which  they  are  nour- 
ished, the  sources  from  which  this  food  is  derived,  and  the  transfor- 
mations it  undergoes  in  their  system.  It  is  in  vegetable  digestion, 
or,  to  use  a  better  term,  in  assimilation,  that  the  essential  nature  of 
vegetation  is  to  be  sought,  since  it  is  in  this  process  alone  that  min- 
eral, unorganized  matter  is  converted  into  the  tissue  of  plants  and 
other  forms  of  organized  matter  (1,  12-16).  From  this  point  of 
view,  therefore,  the  reciprocal  relations  and  influences  of  the  min- 
eral, vegetable,  and  animal  kingdoms  may  be  most  advantageously 
contemplated,  and  the  office  of  plants  in  the  general  economy  of  the 
world  best  understood.  This  portion  of  general  physiology  is  inti- 
mately connected  with  chemistry,  and  some  knowledge  of  that  sci- 
ence is  requisite  for  understanding  it.  We  are  here  restricted  to 
the  bare  statement  of  the  leading  facts  which  are  thought  to  be 
established,  and  the  more  important  deductions  which  may  be  drawn 
from  them. 

317.  While  the  organs  of  vegetation  have  been  considered  ana- 
tomically and  morphologically,  or  in  view  of  their  structure  and 
development,  still  the  leading  points  of  their  physiology,  or  connected 
action  in  the  life  and  growth  of  the  plant,  have  from  time  to  time 
been  explained  or  assumed. 

318.  The  functions  of  nutrition,  which,  in  the  higher  animals, 
comprise  a  variety  of  distinct  processes,  are  reduced  to  the  greatest 
degree  of  simplicity  in  vegetables.  Imbibition,  assimilation,  and 
growth  essentially  include  the  whole. 

319.  Plants  absorb  their  food,  entirely  in  a  liquid  or  gaseous  form, 
by  imbibition,  according  to  the  law  of  endosmosis  (40),  through  the 


178  THE    FOOD    AND    NUTRITION    OF    PLANTS. 

walls  of  the  cells  that  form  the  surface,  principally  those  of  the 
newest  roots  and  their  fibrils  (133).  The  fluid  absorbed  by  the 
roots,  mingled  in  the  cells  with  some  previously  assimilated  matter 
they  contain  in  solution  (26,  79),  is  diffused  by  exosmosis  and  endos- 
mosis  from  cell  to  cell,  rising  principally  in  the  wood  (224,  230)  ; 
and  is  attracted  into  the  leaves  (or  to  other  parts  of  the  surface  of 
the  plant  exposed  to  the  air  and  light)  by  the  exhalation  which 
takes  place  from  them  (314),  and  the  consequent  inspissation  of  the 
sap.  Here,  exposed  to  the  light  of  the  sun,  the  crude  sap  is  assimi- 
lated, or  converted  into  organizable  matter  (79)  ;  and,  thus  prepared 
to  form  vegetable  tissue  or  any  organic  product,  the  elaborated  fluid 
is  attracted  into  growing  parts  by  endosmosis,  in  consequence  of  its 
consumption  and  condensation  there,  or  is  diffused  through  the  newer 
tissues.  There  is  no  movement  in  plants  of  the  nature  of  the  cir- 
culation in  animals.  Even  in  the  so-called  vessels  of  the  latex 
there  is  merely  a  mechanical  flow  from  the  turgid  tubes  towards  the 
place  where  the  liquid  is  escaping  when  wounded,  or  from  a  part 
placed  under  increased  pressure  (63).  The  only  circulation,  or 
directly  vital  movement  of  fluid,  in  vegetable  tissue,  is  the  cyclosis, 
or  the  system  of  currents  in  the  layer  of  protoplasm  in  young  and 
active  cells  (36)  :  this  movement  is  confined  to  the  individual  cell, 
and  can  have  no  influence  in  the  transference  of  the  sap  from  cell 
to  cell.  Respiration  is  likewise  a  function  of  animals  alone.  What 
is  generally  so  called  in  vegetables  is  connected  with  assimilation, 
and  is  of  entirely  different  physiological  significance,  as  will  pres- 
ently be  shown.  None  of  the  secretions  of  plants  appeal',  like 
many  of  those  of  animals,  to  play  any  part,  at  least  any  essential 
part,  in  nutrition.  Many,  if  not  all  of  them,  are  purely  chemical 
transformations  of  the  general  assimilated  products  of  plants,  —  are 
excretions  rather  than  secretions  (88  -  90). 

320.  The  appropriation  of  assimilated  matter  in  vegetable  growth, 
and  the  production  and  multiplication  of  cells,  which  make  up  the 
fabric  of  the  plant,  have  already  been  treated  of  (25-34).  We 
have  now  mainly  to  consider  what  the  food  of  plants  is,  whence  it  is 
derived,  and  how  it  is  elaborated. 


THEIR    ELEMENTARY    CONSTITUENTS.  179 


Sect.  II.  The  Food  and  the  Elementary  Composition 
of  Plants. 

321.  The  Food  and  the  elementary  composition  of  plants  stand 
in  a  necessary  relation  to  each  other.  Since  it  is  not  to  be  sup- 
posed that  plants  possess  the  power  of  creating  any  simple  element, 
whatever  they  consist  of  must  have  been  derived  from  without. 
Their  composition  indicates  their  food,  and  vice  versa.  If  we  have 
learned  the  chemical  composition  of  a  vegetable,  and  also  what  it 
gives  back  to  the  soil  and  the  air,  Ave  know  consequently  what  it 
must  have  derived  from  without,  that  is,  its  food.  Or,  if  we  have 
ascertained  Avhat  the  plant  takes  from  the  soil  and  air,  and  what  it 
returns  to  them,  we  have  learned  its  chemical  composition,  namely, 
the  difference  between  these  two.  And  when  we  compare  the  na- 
ture and  condition  of  the  materials  which  the  plant  takes  from  the 
soil  and  the  air  with  what  it- gives  back  to  them,  we  may  form  a 
correct  notion  of  the  influence  of  vegetation  upon  the  mineral  king- 
dom. By  considering  the  materials  of  which  plants  are  composed, 
we  may  learn  what  their  food  must  necessarily  contain. 

322.  The  Constituents  Of  Plants  are  of  two  kinds  ;  the  earthy  or  in- 
organic, and  the  organic.  It  has  been  stated  (93)  that  various 
earthy  matters,  dissolved  by  the  water  which  the  roots  absorb,  are 
drawn  into  the  plant,  and  at  length  deposited  in  the  wood,  leaves, 
&c.  These  form  the  ashes  which  are  left  on  burning  a  leaf  or  a 
piece  of  wood.  Although  these  mineral  matters  are  often  turned 
to  account  by  the  plant,  and  some  of  them  are  necessary  in  the 
formation  of  certain  products,  (as  the  silex  which  gives  needful 
firmness  to  the  stalk  of  Wheat,  and  the  phosphates  which  are  found 
in  the  grain,)  yet  none  of  them  are  essential  to  simple  vegetation, 
which  may,  to  a  certain  extent,  proceed  without  them.  These 
materials,  the  presence  of  which  is  in  some  sort  accidental,  although 
for  certain  purposes  essential,  are  distinguished  as  the  earthy,  or 
mineral,  or  inorganic  constituents  of  plants.  This  class  may 
be  left  entirely  out  of  view  for  the  present.  But  the  analysis  of 
any  newly  formed  vegetable  tissue,  or  of  any  part  of  the  plant, 
such  as  a  piece  of  Avood,  after  the  incrusting  mineral  matter  has 
been  chemically  removed,  invariably  yields  but  three  or  four  ele- 
ments. These,  which  are  indispensable  to  vegetation,  and  make 
up  at  least  from  eighty-eight  to  ninety-nine  per  cent  of  every  vege- 


180  THE   FOOD  AND  NUTRITION   OF  PLANTS. 

table  substance,  are  termed  the  universal,  organic  constituents  of 
plants.  They  are  Carbon,  Hydrogen,  Oxygen,  and  Nitrogen  (10, 
27).  The  proper  vegetable  structure,  that  is,  the  tissue  itself, 
consists  of  only  three  of  these  elements,  namely,  carbon,  hydrogen, 
and  oxygen ;  while  the  fourth,  nitrogen,  is  an  essential  constituent 
of  the  protoplasm,  which  plays  so  important  a  part  in  the  formation 
of  the  cells  and  is  an  element  of  one  class  of  vegetable  products. 

323.  The  Organic  Constituents.  These  four  elements  must  be  fur- 
nished by  the  food  upon  which  the  vegetable  lives  ;  —  they  must 
be  drawn  from  the  soil  and  the  air ;  in  some  cases,  doubtless,  from 
the  latter  source,  as  in  Epiphytes,  or  Air-plants  (149),  but  gener- 
ally and  principally  by  absorption  through  the  roots.  The  plant's 
nourishment  is  wholly  received  either  in  the  gaseous  or  the  liquid 
form  ;  for  the  leaves  can  imbibe  air  or  vapor  only,  and  the  roots  are 
incapable  of  taking  in  particles  of  solid  matter,  however  minutely  di- 
vided (40,  133). 

324.  In  whatever  mode  imbibed,- evidently  the  main  vehicle  of 
the  plant's  nourishment  is  water,  which  as  a  liquid  or  as  vapor  is 
continually  in  contact  with  its  roots,  and  in  the  state  of  vapor  always 
surrounds  its  leaves.  We  have  seen  how  copiously  water  is  taken 
up  by  the  growing  plant,  and  have  formed  some  general  idea  of  its 
amount  by  the  quantity  that  is  exhaled  unconsumed  by  the  leaves 
(313).  But  pure  water,  although  indispensable,  is  insufficient  for 
the  nourishment  of  plants.  It  consists  of  oxygen  and  hydrogen  ; 
and  therefore  may  furnish,  and  doubtless  does  principally  furnish, 
these  two  essential  elements  of  the  vegetable  structure.  But  it  can- 
not supply  what  it  does  not  itself  contain,  namely,  the  carbon  and 
nitrogen  which  the  plant  also  requires. 

325.  Yet  the  question  arises,  whether  the  water  which  the  plant 
actually  imbibes  contains  in  fact  a  quantity  of  these  remaining 
elements.  Though  pure  water  cannot,  may  not  rain-water  supply 
the  needful  carbon  and  nitrogen  ?  It  is  evident  that,  if  the  water 
which  in  such  large  quantities  rises  through  the  plant,  and  is  ex- 
haled from  its  leaves,  contain  even  a  very  minute  quantity  of  these 
ingredients,  in  such  a  form  that  they  may  be  detained  when  the 
superfluous  water  is  exhaled,  this  might  furnish  the  whole  organic 
food  of  the  vegetable ;  since  the  plant  may  condense  and  accumu- 
late the  carbon  and  nitrogen,  just  as  the  extremely  minute  quantity 
of  earthy  matter  which  the  water  contains  is  in  time  largely  accu- 
mulated in  the  leaves  and  wood. 


SOURCE   OF   THEIR    ORGANIC    CONSTITUENTS.  181 

326.  As  respects  the  nitrogen,  nearly  seventy-nine  per  cent  of 
the  atmosphere  consists  of  this  gas  in  an  uncombined  or  free  state, 
that  is,  merely  mingled  with  oxygen.  And,  being  soluble  to  some 
extent  in  water,  every  rain-drop  that  falls  through  the  air  absorbs 
and  brings  to  the  ground  a  minute  quantity  of  it,  which  is  therefore 
necessarily  introduced  into  the  plant  with  the  water  which  the  roots 
imbibe.  This  accounts  for  the  free  nitrogen  which  is  always  pres- 
ent in  plants. 

327.  The  plant  also  receives  nitrogen  in  the  form  of  ammonia 
(or  hartshorn),  a  compound  of  hydrogen  and  nitrogen,  which  is 
always  produced  when  any  animal  and  almost  any  vegetable  sub- 
stance decays,  and  which,  being  very  volatile,  continually  rises  into 
the  air  from  these  and  other  sources.  Besides,  it  appears  to  be 
formed  in  the  atmosphere,  through  electrical  action  in  thunder-storms 
(in  the  form  of  nitrate  of  ammonia).  The  extreme  solubility  of  am- 
monia and  all  its  compounds  prevents  its  accumulation  in  the  atmos- 
phere, from  which  it  is  greedily  absorbed  by  aqueous  vapor,  and 
brought  down  to  the  ground  by  rain.  That  the  roots  actually  ab- 
sorb it  may  be  inferred  from  the  familiar  facts,  that  plants  grow 
most  luxuriantly  when  the  soil  is  supplied  with  substances  which 
yield  much  ammonia,  such  as  animal  manures ;  and  that  ammonia 
may  be  detected  in  the  juices  of  almost  all  plants.  That  the  am- 
monia in  the  air,  and  the  nitre  almost  everywhere  formed  in  a  fertile 
soil,  and  not  the  free  nitrogen  of  the  atmosphere,  take  the  principal 
part  in  the  formation  of  the  protoplasm  and  other  quaternary  ele- 
ments of  plants,  is  demonstrated  by  BoussingaultTs  experiments, 
showing  that  a  seedling  from  which  all  nitrogen  is  excluded  except 
the  free  nitrogen  of  the  air,  as  it  vegetates  does  not  increase  the 
amount  of  azotized  matter  it  originally  had  in  the  seed,  but  dimin- 
ishes it.*  Rain-water,  therefore,  contains  the  third  element  of 
vegetation,  namely,  nitrogen,  both  in  a  separate  form  and  in  that  of 
ammonia,  &c. 

328.  The  source  of  the  remaining  constituent,  carbon,  is  still  to 
be  sought.  Of  this  element  plants  must  require  a  copious  supply, 
since  it  forms  much  the  largest  portion  of  their  bulk.  If  the  carbon 
of  a  leaf  or  of  a  piece  of  wood  be  obtained  separate  from  the  other 
organic  elements,  —  which  may  be  done  by  charring,  that  is,  by 
heating  it  out  of  contact  with  the  air,  so  as  to  drive  off  the  oxygen, 

*  Comptes  Rendus,  November  28,  1853,  and  Ann.  Sci.  Naturdles,  ser.  4,  Vol. 
1  &  2  (1854) ;  also  Vol.  7  (1857),  showing  the  part  which  nitre  plays. 
16 


182  THE    FOOD    AND    NUTRITION    OF   PLANTS. 

hydrogen,  and  carbon,  —  although  a  small  part  of  the  carbon  is 
necessarily  lost  in  the  operation,  yet  what  remains  perfectly  pre- 
serves the  shape  of  the  original  body,  even  to  that  of  its  most 
delicate  cells  and  vessels.  With  the  exception  of  the  ashes,  this 
consists  of  carbon,  or  charcoal,  amounting  to  from  forty  to  sixty 
per  cent,  by  weight,  of  the  original  material.  Carbon  is  itself  a 
solid,  absolutely  insoluble  in  water,  and  therefore  incapable  of  as- 
sumption by  the  plant.  The  chief,  if  not  the  only,  fluid  compound 
of  carbon  which  is  naturally  presented  to  the  plant,  is  that  of  car- 
bonic acid  gas,  which  consists  of  carbon  united  with  oxygen.  This 
gas  makes  up  on  the  average  one  2500th  of  the  bulk  of  the  at- 
mosphere ;  from  which  it  may  be  directly  absorbed  by  the  leaves. 
But,  being  freely  soluble  in  water  up  to  a  certain  point,  it  must  also 
be  earned  down  by  the  rain  and  imbibed  by  the  roots.  The  car- 
bonic acid  of  the  atmosphere  is  therefore  the  great  source  of  carbon 
for  vegetation. 

329.  It  appears,  then,  that  the  atmosphere  —  considering  water 
in  the  state  of  vapor  to  form  a  component  part  of  it  —  contains  all 
the  essential  materials  for  the  growth  of  vegetables,  and  in  the  form 
best  adapted  to  their  use,  namely,  in  the  fluid  state.  It  furnishes 
water,  which  is  not  only  food  itself,  inasmuch  as  it  supplies  oxygen 
and  hydrogen,  but  is  likewise  the  vehicle  of  the  others,  conveying 
to  the  roots  what  it  has  gathered  from  the  air,  namely,  the  requisite 
supply  of  nitrogen,  either  as  such  or  in  the  form  of  ammonia,  and 
of  carbon  in  the  form  of  carbonic  acid. 

330.  These  essential  elements,  the  whole  proper  food  of  plants, 
may  he  absorbed  by  the  leaves  directly  from  the  air,  in  the  state  of 
gas  or  vapor.  Doubtless  most  plants  actually  take  in  no  small  part 
of  their  food  in  this  way.  Drooping  foliage  may  be  revived  by 
sprinkling  with  water,  or  by  exposure  to  a  moist  atmosphere.  A 
vigorous  branch  of  the  common  Live-for-ever  (Sedum  Telephium), 
or  of  many  similar  plants,  it  is  well  known,  will  live  and  grow  for  a 
whole  season  when  pinned  to  a  dry  and  bare  wall ;  and  the  Epi- 
phytes, or  Air-plants  (149),  as  they  are  aptly  called,  must  derive 
their  whole  sustenance  immediately  from  the  air  ;  for  they  have  no 
connection  with  the  ground.  That  leaves  absorb  carbonic  acid 
directly  from  the  air  is  readily  shown  (348). 

331.  But,  as  a  general  statement,  it  may  be  said  that  plants,  al- 
though they  derive  their  food  from  the  air,  receive  it  mainly  through 
their  roots.     The  aqueous  vapor,  condensed  into  rain  or  dew,  and 


SOURCE    OF   THEIR    ORGANIC    CONSTITUENTS.  183 

bringing  with  it  to  the  ground  a  portion  of  carbonic  acid,  and  of 
nitrogen  or  ammonia,  &c,  supplies  the  appropriate  food  of  the  plant 
to  the  rootlets  (sometimes  in  a  liquid,  but  also  much  of  it  in  a  gaseous 
form).  Imbibed  by  these,  it  is  conveyed  through  the  stem  and  into 
the  leaves,  where  the  superfluous  water  is  restored  to  the  atmosphere 
by  exhalation,*  while  the  residue  is  converted  into  the  proper  nour- 
ishment and  substance  of  the  vegetable. 

332.  The  atmosphere  is  therefore  the  great  storehouse  from 
which  A^egetables  derive  their  nourishment ;  and  it  might  be  clearly 
shown  that  all  the  constituents  of  plants,  excepting  the  small  earthy 
portion  that  many  can  do  without,  have  at  some  period  formed  a 
part  of  the  atmosphere.  The  vegetable  kingdom  represents  an 
amount  of  matter,  which  plants  have  withdrawn  from  the  air,  organ- 
ized, and  confined  for  a  time  to  the  surface. 

333.  Does  it  therefore  follow,  that  the  soil  merely  serves  as  a 
foothold  to  plants,  and  that  all  vegetables  obtain  their  whole  nour- 
ishment directly  from  the  atmosphere  ?  This  must  have  been  the 
case  with  the  first  plants  that  grew,  when  no  vegetable  or  animal 
matter  existed  in  the  soil ;  and  no  less  so  with  the  first  vegetation 
that  covers  small  volcanic  islands  raised  in  our  own  times  from  the 
sea,  or  the  surface  of  lava  thrown  from  ordinary  volcanoes.  No 
vegetable  matter  is  brought  to  these  perfectly  sterile  mineral  soils, 
except  the  minute  portion  contained  in  the  seeds  wafted  thither  by 
winds  or  waves.  And  yet  in  time  a  vast  quantity  is  produced,  which 
is  represented  not  only  by  the  existing  vegetation,  but  by  the  mould 
that  the  decay  of  previous  generations  has  imparted  to  the  soil.  We 
arrive  at  the  same  result  by  the  simple  experiment  of  causing  a 

*  The  water  exhaled  may  be  again  absorbed  by  the  roots,  laden  with  a  new 
supply  of  the  other  elements  from  the  air,  again  exhaled,  and  so  on ;  as  is 
beautifully  illustrated  by  the  cultivation  of  plants  in  closed  Ward  cases,  where 
plants  are  seen  to  flourish  for  a  long  time  with  a  very  limited  supply  of  water, 
every  particle  of  which  (except  the  small  portion  actually  consumed  by  the 
plants)  must  pass  repeatedly  through  this  circulation.  This  vegetable  micro- 
cosm well  exhibits  the  actual  relations  of  water,  &c.  to  vegetation  on  a  large 
scale  in  nature  ;  where  the  water  is  alternately  and  repeatedly  raised  by  evapo- 
ration and  recondensed  to  such  extent  that  what  actually  falls  in  rain  is  esti- 
mated to  be  re-evaporated  and  rained  down  (on  an  average  throughout  the 
world)  ten  or  fifteen  times  in  the  course  of  a  year.  In  this  way  the  atmosphere 
is  repeatedly  washed  by  the  rain ;  and  those  vapors  ivashed  out  which  else  by 
their  accumulation  would  prove  injurious  to  men  and  animals,  and  conveyed  to 
the  roots  of  plants,  which  they  are  especially  adapted  to  nourish. 


184  THE    FOOD    AND    NUTRITION    OF   PLANTS. 

seed  of  known  weight  to  germinate  on  powdered  flints,  or  on  a  soil 
which  has  been  heated  to  redness,  and  watering  it  with  rain-water 
alone.  "When  the  young  plant  has  attained  all  the  development  it  is 
capable  of  under  these  circumstances,  it  will  be  found  to  weigh  (after 
due  allowance  for  the  silex  it  may  have  taken  up)  perhaps  fifty  or 
one  hundred  times  as  much  as  the  original  seed.  There  can  be  no 
question  as  to  the  source  of  this  vegetable  matter  in  all  these  cases. 
The  requisite  materials  exist  in  the  air.  Plants  possess  the  peculiar 
faculty  of  drawing  them  from  the  air.  The  air  must  have  furnished 
the  whole.  This  conclusion  is  amply  confirmed  by  a  great  variety  of 
familiar  facts  ;  such  as  the  continued  accumulation  of  vegetable  mat- 
ter hi  peat-bogs,  and  of  mould  in  neglected  fields,  in  old  forests,  and 
generally  wherever  vegetation  is  undisturbed.  Since  this  rich 
mould,  instead  of  diminishing,  regularly  increases  with  the  age  of 
the  forest  and  the  luxuriance  of  vegetation,  the  trees  must  have 
drawn  from  the  air,  not  only  the  vast  amount  of  carbon,  &c.  that  is 
stored  up  in  their  trunks,  but  an  additional  quantity  which  is  im- 
parted to  the  soil  in  the  annual  fall  of  leaves,  &c. 

334.  Still  it  by  no  means  follows  that  each  plant  draws  all  its 
nourishment  directly  from  the  air.  This  unquestionably  happens 
in  some  of  the  special  cases  just  mentioned ;  with  Air-plants,  and 
with  those  that  first  vegetate  on  volcanic  earth,  bare  rocks,  naked 
walls,  or  pure  sand.  But  it  is  particularly  to  be  remarked,  that 
only  certain  tribes  of  jdants  will  continue  to  live  under  such  cir- 
cumstances, and  that  none  of  the  vegetables  most  useful  as  food 
for  man  or  the  higher  animals  will  thus  thrive  and  come  to  matu- 
rity. In  nature,  the  races  of  plants  that  will  grow  at  the  entire 
expense  of  the  air,  such  as  Lichens,  Mosses,  Ferns,  and  certain 
tribes  of  succulent  Flowering  plants,  gradually  form  a  soil  of  vege- 
table mould  during  their  life,  which  they  increase  in  their  decay ; 
and  the  successive  generations  live  more  vigorously  upon  the  in- 
heritance, being  supported  partly  upon  what  they  draw  from  the 
air,  and  partly  upon  the  ancestral  accumulation  of  vegetable  mould. 
Thus,  each  generation  may  enrich  the  soil,  even  when  consisting  of 
plants  that  draw  largely  upon  vegetable  matter  thus  accumulated ; 
for  these  annually  restore  a  portion  by  their  dead  leaves,  &c,  and 
when  they  die  they  may  bequeath  to  the  soil,  not  only  all  that  they 
took  from  it,  but  all  that  they  drew  from  the  air.  It  is  in  this  way 
that  the  lower  tribes  and  so-called  useless  plants  create  a  soil,  which 
will  in  time  support  the  higher  plants,  of  immediate  importance  t^ 


SOURCE    OF   THEIR    ORGANIC    CONSTITUENTS.  185 

man  and  the  higher  animals,  but  which  could  never  grow  and  per- 
fect their  fruit,  if  left,  like  their  humble  but  indispensable  predeces- 
sors, to  derive  an  unaided  subsistence  directly  from  the  inorganic 
world.  While  it  is  strictly  true,  therefore,  that  all  the  organic  ele- 
ments have  been  originally  derived  from  the  air,  it  is  not  true  that 
what  is  contained  in  almost  any  given  plant,  or  in  any  one  crop,  is 
immediately  drawn  from  this  source.  A  part  of  it  is  thus  supplied, 
but  in  proportions  varying  greatly  in  different  species  and  under 
different  circumstances.  Undisturbed  vegetation  consequently  tends 
always  to  enrich  the  soil.  But  in  agriculture  the  crop  is  ordinarily 
removed  from  the  land,  and  with  it  not  only  what  it  has  taken  from 
the  earth,  but  also  what  it  has  drawn  from  the  air ;  and  the  soil  is 
accordingly  impoverished.  Hence  the  farmer  finds  it  necessary 
to  follow  the  example  of  nature,  and  to  restore  to  the  land,  in  the 
form  of  manure,  an  amount  substantially  equivalent  to  what  he 
takes  away. 

335.  The  mode  in  which  vegetable  mould  is  turned  to  account 
by  growing  plants  has  not  yet  been  sufficiently  investigated.  Ac- 
cording to  Liebig,  the  decaying  vegetable  matter  is  not  employed 
until  it  has  been  resolved  into  its  original  inorganic  elements, 
namely,  into  water,  carbonic  acid,  ammonia,  &c. ;  which  are  imbibed 
by  the  roots  both  directly  in  the  gaseous  state,  and  when  taken  up  by 
the  water  as  it  percolates  through  the  soil.*  Others  suppose  that  a 
portion  of  the  food  which  plants  derive  from  decaying  vegetable 
matter  may  consist  of  soluble,  still  organic  compounds.  The  econ- 
omy of  the  greenless  parasitic  plants  (152)  is  adduced  in  confirma- 
tion of  this  view  :  but  these  are  nourished  by  the  foster  plant  just  as 
its  own  flowers  are  nourished.  Decisive  evidence  to  the  point  is 
furnished  by  Fungi,  the  greater  part  of  which  live  upon  decaying 
organic  matter,  and  have  not  the  power  of  forming  organizable  pro- 


*  While  it  may  be  rightly  said,  that  the  proportion  of  carbonic  acid  in  the 
atmosphere  is  too  minute  directly  to  supply  ordinary  vegetation,  especially 
that  of  esculent  plants,  with  sufficient  carbon,  this  cannot  be  said  of  the  air 
contained  in  the  pores  and  crevices  of  the  soil,  at  least  in  any  fertile  soil.  This 
air  in  the  soil  contains  a  far  larger  proportion  of  carbonic  acid  than  the  atmos- 
phere above ;  the  excess  being  derived  partly  by  direct  absorption  or  by  the 
action  of  rain,  and  in  an  enriched  soil  more  largely  from  the  decay  of  the  mate- 
rials of  former  generations  of  plants.  In  a  recently  manured  soil,  the  carbonic 
acid  ordinarily  amounts  even  to  10  or  20  per  cent.  See  Boussingault  and  Lewy, 
in  Ann.  Sci.  Nat.  ser.  3,  Vol.  19,  p.  13. 
16* 


186  THE    FOOD    AND    NUTRITION    OF    PLANTS. 

ducts  from  inorganic  materials  ;  and  there  is  reason  to  think,  that 
some  Phosnogamous  plants  (of  which  our  Monotropa,  or  Indian  Pipe 
is  one)  are  nourished  in  this  way. 

336.  The  Earthy  Constituents.  The  mineral  substances  which  form 
the  inorganic  constituents  of  plants  (322)  are  furnished  by  the  soil, 
and  are  primarily  derived  from  the  slow  disintegration  and  decom- 
position of  the  rocks  and  earths  that  compose  it.*  These  are  dis- 
solved, for  the  most  part  in  very  minute  proportions,  in  the  water 
which  percolates  the  soil,  (aided,  as  to  the  more  insoluble  earthy 
salts,  by  the  carbonic  acid  which  this  water  contains,)  and  with  this 
water  are  taken  up  by  the  roots.  However  minute  their  proportion 
in  the  water  which  the  roots  imbibe,  the  plant  concentrates  and 
accumulates  them,  by  the  exhalation  of  the  water  from  the  leaves, 
until  they  amount  to  an  appreciable  quantity,  often  to  a  pretty  large 
percentage,  of  the  solid  matter  of  the  vegetable.  As  might  be  ex- 
pected (312),  the  leaves  contain  a  much  larger  amount  of  ashes,  or 
earthy  matter,  than  the  wood,  and  herbaceous  plants  more  than  trees, 
in  proportion  to  their  weight  when  dry.f 

337.  The  ashes  left  after  combustion  are  mostly  composed  of 
the  "  alkaline  chlorides,  with  the  bases  of  potash  and  soda,  earthy 
and  metallic  phosphates,  caustic  or  carbonate  of  lime  and  magnesia, 
silica,  and  oxides  of  iron  and  of  manganese.  Several  other  sub- 
stances are  also  met  with  there,  but  in  quantities  so  small  that  they 
may  be  neglected."  Different  species  growing  in  the  same  soil 
appear  to  take  in  some  portion  of  all  such  materials  as  are  natu- 


*  According  to  Licbig,  the  quantity  of  potash  contained  in  a  layer  of  soil 
formed  by  the  disintegration  of  40,000  square  feet  of  the  following  rocks,  &c, 
to  the  depth  of  twenty  inches,  is  as  follows.  This  quantity  of  Felspar  (a  large 
component  of  granite,  &c.)  contains  .  .  .  1,152,000  lbs. 

Clinkstone,  .....       from  200,000  to  400,000   " 

Basalt,  .....  "      47,500  "     75,000   " 

Clay-slate,  ....."     100,000  "  200,000   " 

Loam,  .  .  .  .  .  .     "       87,000  "  300,000    " 

The  silex  yielded  to  the  soil  by  the  gradual  decomposition  of  granite  and 
other  rocks  is  in  the  form  of  a  silicate  of  potash  or  other  alkali,  which,  though 
insoluble  in  pure  water,  is  slowly  acted  upon  and  dissolved  by  the  united  action 
of  water  and  carbonic  acid,  or  more  largely  by  water  impregnated  with  carbon- 
ate of  potash,  which  is  abundantly  liberated  during  the  natural  decomposition 
of  these  rocks. 

t  The  subjoined  results,  selected  from  Boussingault,  exhibit  in  a  tabular  form 
the  relative  quantities  of  organic  and  inorganic  constituents  in  several  kinds  of 


THEIR    EARTHY    CONSTITUENTS. 


187 


rally  presented  to  them  in  solution,  but  not,  however,  in  the  same 
proportions,  nor  in  proportion  to  the  relative  solubility  of  these 
several  substances ;  while,  on  the  other  hand,  the  same  species  in 
different  localities,  and  also  each  of  its  particular  parts  or  organs, 
contains,  or  tends  to  contain,  the  same  mineral  constituents  in  nearly 
the  same  proportion.  One  base,  however,  is  often  substituted  for 
another,  equivalent  for  equivalent,  as  magnesia  for  lime,  soda  for 
potash.  The  roots,  therefore,  appear  to  have  a  certain  power  of 
selection  in  respect  to  these  mineral  materials.  Nor  is  it  a  valid 
objection  to  this  view,  that  they  absorb  poisons  which  destroy  them. 
These  are  either  organic  products,  such  as  opium ;  or  else  are  cor- 
rosive substances,  such  as  sulphate  of  copper,  which  disorganize  the 
rootlets.  For  mutilated  roots  or  stems  absorb  all  dissolved  materials 
of  the  proper  density  that  are  presented  to  them,  not  only  in  much 
larger  quantity  (so  long  as  the  cut  is  fresh)  than  do  uninjured  root- 
lets, but  almost  indifferently,  and  in  the  same  proportion  that  they 
absorb  the  water  they  are  dissolved  in. 

338.  In  the  ashes,  only  the  salts  which  resist  the  action  of  heat, 
such  as  the  phosphates,  sulphates,  and  hydrochlorates,  are  in  the 
state  in  which  they  existed  in  the  plant  itself.  A  great  part  of  the 
bases  were  combined  with  organic  acids,  formed  in  the  plant,  and 
most  largely  with  the  oxalic  (86)  :  these  compounds  are  by  incinera- 
tion, or  by  exposure  to  the  air,  principally  converted  into  carbonates. 

339.  It  being  indispensable  to  its  well-being  that  a  plant  should 
find  in  the  soil  such  mineral  matters  as  are  necessary  to  its  growth, 
we  perceive  why  various  species  Avill  only  flourish  in  particular  soils 
or  situations  ;  why  plants  which  take  up  common  salt,  &c.  are  re- 
stricted to  the  sea-shore  and  to  the  vicinity  of  salt-springs  ;  why 


herbage,  compared,  in  several  cases,  with  the  root  or  grain.     The  water  was 
previously  driven  off  by  thorough  drying. 


Carbon, 

Hydrogen, 

Oxygen, 

Nitrogen, 

Ashes, 

H 

°| 
-'  Jl 

p.  aj 
c3  ho 

s 

f-s 

<«  3 
°^ 
o 
o 

PS 

Pi 

o 

o 

o 
fk 

44.80 
5.10 

30.50 
2.30 

17.30 

CI 

o 

o 

Peas. 

Clover-hay. 

Be 

a 

u 

% 

si 

48.48 
5.41 

38.79 

0.35 

6.97 

100.00 

1 

46.10 

5.80 

4340 

2.27 

2.43 

100.00 

38.10J  42.75 
5.10      5.77 

30.80    43.58 
4.50      1.66 

21.50      6.24 

43.72 
6.00 

44.88 
1.50 
3.90 

100.00 

45.80 
5.00 

35.57 
2.31 

11.32 
100.00 

46.06 
6.09 

40.53 
4.18 
3.14 

47.53 
4.69 

37.96 
2.06 
7.76 

100.00  100.00  100.00 

100.00 

100.00 

188  THE    FOOD    AND    NUTRITION    OF   PLANTS. 

numerous  weeds  which  grow  chiefly  around  dwellings,  and  follow  the 
footsteps  of  man  and  the  domestic  animals,  flourish  only  in  a  soil 
abounding  in  nitrates  (their  ashes  containing  a  notable  quantity 
either  of  nitrate  of  potash  or  of  lime)  ;  why  the  Vine  requires  alka- 
line manures,  to  replace  the  large  amount  of  tartrate  of  potash  which 
the  grapes  contain ;  and  why  Pines  and  Firs,  the  ashes  of  which 
contain  very  little  alkali,  will  thrive  in  thin  or  sterile  soils,  while  the 
Beech,  Maple,  Elm,  &c.,  abounding  with  potash,  are  only  found  in 
strong  and  fertile  land. 

340.  Where  vegetation  is  undisturbed  by  man,  all  these  needful 
earthy  materials,  which  are  drawn  from  the  soil  during  the  growth 
of  the  herbage  or  forest,  are  in  time  restored  to  it  by  its  decay, 
in  an  equally  soluble  form,  along  with  organic  matter  which  the 
vegetation  has  formed  from  the  air.  But  in  cultivation,  the  prod- 
uce is  carried  away,  and  with  it  the  materials  which  have  been 
slowly  yielded  by  the  soil.  "  A  medium  crop  of  Wheat  takes  from 
one  acre  of  ground  about  12  pounds,  a  crop  of  Beans  about  20 
pounds,  and  a  crop  of  Beets  about  11  pounds,  of  phosphoric  acid, 
besides  a  very  large  quantity  of  potash  and  soda.  It  is  obvious  that 
such  a  process  tends  continually  to  exhaust  arable  land  of  the 
mineral  substances  useful  to  vegetation  which  it  contains,  and  that  a 
time  must  come,  when,  without  supplies  of  such  mineral  matters,  the 

land  Avould  become  unproductive  from  their  abstraction In 

the  neighborhood  of  large  and  populous  towns,  for  instance,  where 
the  interest  of  the  farmer  and  market-gardener  is  to  send  the  largest 
possible  quantity  of  produce  to  market,  consuming  the  least  possible 
quantity  on  the  spot,  the  want  of  saline  principles  in  the  soil  would 
very  soon  be  felt,  were  it  not  that  for  every  wagon-load  of  greens 
and  carrots,  fruit  and  potatoes,  corn  and  straw,  that  finds  its  way 
into  the  city,  a  wagon-load  of  dung,  containing  each  and  every  one 
of  these  principles  locked  up  in  the  several  crops,  is  returned  to  the 
land,  and  proves  enough,  and  often  more  than  enough,  to  replace  all 
that  has  been  carried  away  from  it."  *  The  loss  must  either  be 
made  up  by  such  equivalent  return,  or  the  land  must  lie  fallow  from 

*  Boussingault,  Eeonomie  Rurale  :  from  the  Engl.  Trans.,  p.  493.  Further  : 
"  It  may  be  inferred  that,  in  the  most  frequent  case,  namely,  that  of  arable 
lands  not  sufficiently  rich  to  do  without  manure,  there  can  be  no  continuous 
[independent]  cultivation  without  annexation  of  meadow;  in  other  words,  one 
part  of  the  farm  must  yield  crops  without  consuming  manure,  so  that  this  may 
replace  the  alkaline  and  earthy  salts  which  are  constantly  withdrawn  by  sue- 


THEIR    EARTHY    CONSTITUENTS. 


189 


time  to  time  until  these  soluble  substances  are  restored  by  further 
disintegration  of  the  materials  of  the  soil :  or  meanwhile  the  more 
exhausting  crops  may  be  alternated  with  those  that  take  least  from 
the  soil  and  most  from  the  air ;  or  with  one  which,  like  clover, 
although  it  takes  up  77  pounds  of  alkali  per  acre,  may  be  consumed 
on  the  field,  so  as  to  restore  most  of  this  alkali  in  the  manure  for  the 
succeeding  crop. 

341.  It  has  been  asserted  that  the  advantage  of  preceding  a 
wheat  crop  by  one  of  Leguminous  plants  (such  as  Peas,  Clover, 
Lucerne,  &c),  or  of  roots  or  tubers,  is  owing  to  the  fact,  that  these 
leave  the  phosphates,  &c.  nearly  untouched  for  the  wheat  which  is 
to  follow,  and  which  largely  abstracts  them.  The  results  of  Bous- 
singault's  experiments  and  analyses  show  that  these  products  are 
far  from  having  the  deficiency  of  phosphates  which  was  alleged. 
"  For  example,  beans  and  haricots  take  20  and  13.7  pounds  of 
phosphoric  acid  from  every  acre  of  land ;  potatoes  and  beet-root 
take  11  and  12.8  pounds  of  that  acid,  exactly  what  is  found  in  a 
crop  of  wheat.  Trefoil  is  equally  rich  in  phosphates  with  the 
sheaves   of  corn   that   have    gone   before   it."  *      His   further   re- 


cessive harvests  from  another  part.  Lands  enriched  by  rivers  alone  permit  of  a 
total  and  continued  export  of  their  produce  without  exhaustion.  Such  are  the 
fields  fertilized  by  the  inundations  of  the  Nile  ;  and  it  is  difficult  to  form  an  idea 
of  the  prodigious  quantities  of  phosphoric  acid,  magnesia,  and  potash,  which, 
in  a  succession  of  ages,  have  passed  out  of  Egypt  with  her  incessant  exports  of 
corn."  —  p.  503. 

*  Boussingault,  I.  c,  p.  497.  —  Subjoined  is  a  table,  from  the  same  work,  of 
the  percentage  of  Mineral  Substances  taken  up  from  the  soil  by  various  plants  grown 
at  Bechelbronn. 


Substances  which 
yielded  the  Ashes. 

Acids. 

1 
o 

— 
2.7 

a 
j 

1.8 

0) 

0 

to 
si 

a 

5.4 

o 
Pm 

51.5 

c3 

■3 

o 

TO 

(3 

53 

a  z 

o  a 

ffl  3 

o 

-  n 
o    „ 

is  u 

"5 
o 

.a 
u 

8 

§ 

si 

Of 

s 

3 
A 
p. 
o 
si 

11.3 

Potatoes, 

13.4;     7.1 

traces 

5.6 

0.5 

0.7 

Man  gel-Wurzel, 

16.1 1   1.6 

6.1 

5.2 

7.0 

4.4 

39.0 

6.0 

8.0 

2.5 

4.2 

Turnips, 

14.0  10.9 

6.0 

2.9 

10.9 

4.3 

33.7 

4.1 

6.4 

1.2 

5.5 

Potato-tops, 

11.0.   22 

10.8 

1.6 

2.3 

1.8 

44.5 

traces 

13  0 

5.2 

7.6 

Wheat, 

0.0    1.0 

47.0 

traces 

2.9 

15.9 

29.5 

traces 

1.3 

0.0 

2.4 

Wheat-straw, 

00 

1.0 

3.1 

0.6 

8.5 

5.0 

9.2 

0.3 

67.6 

1.0 

3.7 

Oats, 

1.7 

1.0 

14.9 

0.5 

3.7 

7.7 

12.9 

0.0 

53.3 

1.3 

3.0 

Oat-straw, 

3.2    4.1 

3.0 

4.7 

8.3 

2.8 

24.5 

44 

40.0 

2.1 

29 

Clover, 

25.0    2.5 

6.3 

2.6 

246 

6.3 

266 

0.5 

5.3 

0.3 

00 

Peas, 

0.5    4.7 

30.1 

1.1 

10.1 

11.9 

35.3 

2.5 

1.5 

traces 

2.3 

French  beans, 

3.3    1.3 

26.8 

0.1 

5.8 

11.5  49.1 

00 

1.0 

traces 

1.1 

Horse  beans, 

10    1.6 

134.2 

0.7 

5.1  i   8.6i45.2 

00 

05 

traces 

3  1 

190  THE   FOOD    AND    NUTRITION    OF    PLANTS. 

searches  seem  to  show  that  these  crops  exhaust  the  soil  less  than 
the  cereal  grains,  in  part  at  least,  on  account  of  the  large  quantity 
of  organic  matter,  rich  in  nitrogen,  which  they  leave  to  be  incor- 
porated with  the  soil.  The  theory  of  rotation  in  crops,  founded  by 
De  Candolle  on  the  assumption  that  excretions  from  the  roots  of  a 
plant  accumulate  in  the  soil  until  in  time  they  become  injurious 
to  that  crop,  but  furnish  appropriate  food  for  a  different  species, 
is  entirely  abandoned  as  an  explanation ;  and  even  the  fact  that 
such  excretions  are  formed,  at  least  to  any  considerable  extent,  is 
not  made  out.  That  they  could  accumulate  and  remain  in  the  soil 
without  undergoing  decomposition  is  apparently  impossible. 


Sect.  III.     Assimilation,  or  Vegetable  Digestion,  and  its 

Results. 

342.  We  have  reached  the  conclusion,  that  the  universal  food  of 
plants  is  rain-water,  which  has  absorbed  some  carbonic  acid  gas 
and  nitrogen  (partly  in  the  form  of  ammonia  or  of  other  compounds) 
from  the  air,  or  dissolved  them  from  the  remains  of  former  vegeta- 
tion in  the  soil,  whence  it  has  also  taken  up  a  variable  (yet  more  or 
less  essential)  quantity  of  earthy  matter. 

343.  This  fluid,  imbibed  by  the  roots,  and  carried  upwards 
through  the  stem,  receives  the  name  of  sap  or  crude  sap  (79). 
Upon  its  introduction  into  the  plant,  this  is  at  once  mingled  with 
some  elaborated  sap  or  soluble  organized  matter  it  meets  with ; 
thus  becoming  sweet  in  the  Maple,  &c,  and  acquiring  different 
sensible  properties  in  different  species.  This  latter  is  already  elab- 
orated food,  and  may  therefore  be  immediately  employed  in  vegeta- 
ble growth.  But  the  crude  sap  itself  is  merely  raw  material,  unor- 
ganized or  mineral  matter,  as  yet  incapable  of  forming  a  part  of  the 
living  structure.  Its  conversion  into  organized  matter  constitutes 
the  process  of 

344.  Assimilation,  or  what,  from  an  analogy  with  animal  life,  is 
usually  termed  Vegetable  Digestion.  To  undergo  this  important 
change,  the  crude  sap  is  attracted  into  the  leaves,  or  other  green 
parts  of  the  plant,  which  constitute  the  apparatus  of  assimilation, 
where  it  is  exposed  to  the  light  of  the  sun,  under  which  influence 
alone  can  this  change  be  effected.  Under  the  influence  of  solar 
light,  the  fabric  is  itself  constructed,  and  the  chlorophyll,  or  green 


ASSIMILATION*.  191 

matter  of  plants,  upon  which,  or  in  connection  with  winch,  the  light 
exerts  its  wonderful  action,  is  first  developed.  When  plants  are 
made  to  grow  in  insufficient  light,  as  when  potatoes  throw  out  shoots 
in  cellars,  this  green  matter  is  not  formed.  When  light  is  with- 
drawn, it  is  soon  decomposed ;  as  we  see  when  Celery  is  blanched 
by  heaping  the  soil  around  its  stems.  So,  also,  the  naturally  green- 
less  leaves  of  plants  parasitic  upon  the  roots  or  stems  of  other  species 
(152)  have  no  direct  power  of  assimilation,  but  feed  upon  and  grow 
at  the  expense  of  already  assimilated  matter.  But  all  green  parts, 
such  as  the  cellular  outer  bark  of  most  herbs,  act  upon  the  sap  in 
the  same  manner  as  leaves,  even  supplying  their  places  in  plants 
which  produce  few  or  no  leaves,  as  in  the  Cactus,  &c.  Under  the 
influence  of  light,  an  essential  preliminary  step  in  vegetable  digestion 
is  accomplished,  namely,  the  concentration  of  the  crude  sap  by  the 
evaporation  or  exhalation  of  the  now  superfluous  water,  the  mechan- 
ism and  consequences  of  which  have  already  been  considered  (313). 

345.  We  have  now  to  consider  the  further  agency  of  light  in  vege- 
table digestion  itself,  namely,  its  action  in  the  leaf  upon  the  concen- 
trated sap.  Here  it  accomplishes  two  unparalleled  results,  which  es- 
sentially characterize  vegetation,  and  upon  which  all  organized  exist- 
ence absolutely  depends  (1,  1G).  These  are, —  1st.  The  chemical 
decomposition  of  one  or  more  of  the  substances  in  the  sap  which 
contain  oxygen  gas,  and  the  liberation  of  this  oxygen  at  the  ordi- 
nary temperature  of  the  air.  The  chemist  can  liberate  oxygen 
gas  from  its  compounds  only  by  powerful  reagents,  or  by  great 
heat.  2d.  The  transformation  of  this  mineral,  inorganic  food 
into  organic  matter,  —  the  organized  substance  of  living  plants, 
and  consequently  of  animals.  These  two  operations,  although 
separately  stated,  are  in  fact  but  different  aspects  of  one  great 
process.  We  contemplate  the  first,  when  we  consider  what  the 
plant  gives  back  to  the  air;  the  second,  when  we  inquire  what 
it  retains  as  the  materials  of  its  own  growth.  The  concentrated  sap 
is  decomposed ;  the  portion  not  required  in  the  growth  of  the  plant 
is  returned  to  the  air  ;  and  the  remaining  elements  are  at  the  same 
time  rearranged,  so  as  to  form  peculiar  organic  products. 

346.  The  principal  material  given  back  to  the  air,  in  this  pro- 
cess, is  oxygen  gas,*  that  element  of  our  atmosphere  which  alone 


*  A  small  proportion  of  nitrogen  gas  is  likewise  almost  constantly  exhaled 
from  the  leaves  ;  but  this  appears  to  come  from  the  nitrogen  which  the  water 


192  THE   FOOD   AND   NUTRITION    OF   PLANTS. 

renders  it  fit  for  the  breathing  and  life  of  animals.  That  the  foliage 
of  plants  in  sunshine  is  continually  yielding  oxygen  gas  to  the  sur- 
rounding air  has  been  familiarly  known  since  the  days  of  Ingenhouss 
and  Priestley,  and  may  at  any  moment  be  verified  by  simple  experi- 
ment. The  readiest  way  is,  to  expose  a  few  freshly  gathered  leaves 
to  the  sunshine  in  a  glass  vessel  filled  with  water,  and  to  collect  the 
air-bubbles  which  presently  arise  while  the  light  falls  upon  them, 
but  which  cease  to  appear  when  placed  in  shadow.  This  air,  when 
examined,  proves  to  be  free  oxygen  gas.  In  nature,  diffused  day- 
light produces  this  effect ;  but  in  our  experiments,  direct  sunshine  is 
generally  necessary  to  show  it.  What  is  the  source  of  this  oxygen 
gas,  which  is  given  up  to  the  air  just  in  proportion  to  the  vigor  of 
assimilation  in  the  leafy  plant,  or,  in  other  words,  to  the  consumption 
of  crude  sap  ? 

347.  This  will  be  manifest  on  comparing  the  materials  with  the 
general  products  of  vegetation,  —  what  the  plant  takes  as  its  food, 
with  what  it  makes  of  it,  in  growth.  Suppose  the  plant  is  assimi- 
lating its  food  immediately  into  its  fabric,  viz.  into  Cellulose,  or  the 
substance  of  which  its  tissue  consists  (27).  This  matter,  when  in  a 
pure  state,  and  free  from  incrusting  materials,  has  a  perfectly  uni- 
form composition  in  all  plants.  It  is  composed  of  carbon,  hydrogen, 
and  oxygen,  the  latter  two  existing  in  the  same  proportions  as  in 
water.*  It  may  therefore  be  said  to  consist  of  carbon  and  the  ele- 
ments of  water.  These  materials  are  necessarily  furnished  by  the 
plant's  food.  The  mineral  food  of  the  plant,  from  which  its  fabric 
is  made  (329),  is  carbonic  acid  and  water.  If  this  be  decomposed 
in  vegetation,  and  the  carbonic  acid  give  up  its  oxygen,  carbon  and 
the  elements  of  water  remain,  —  the  very  composition  of  cellulose  or 
vegetable  tissue.  Doubtless,  then,  the  oxygen  which  is  rendered  to 
the  air  in  vegetation  comes  from  the  carbonic  acid  which  the  plant 
took  from  the  air  (328). 

348.  This  view  may  be  confirmed  by  direct  experiment.     We 

imbibed  by  the  roots  had  absorbed  from  the  air  (326),  and  which  passes  off  un- 
altered from  the  leaves  when  this  water  is  evaporated,  or  from  nitrogen  in  the 
air  which  the  rootlets  directly  absorb.  In  the  course  of  vegetation,  no  more 
nitrogen  is  given  out  than  what  is  thus  taken  in,  and  probably  not  so  much. 
So  that  the  exhalation  of  nitrogen  may  be  left  out  of  the  general  view  of  the 
changes  which  are  brought  about  in  vegetation. 

*  Cellulose  is  chemically  composed  of  12  equivalents  of  Carbon,  10  of  Hy- 
drogen, and  10  of  Oxygen,  viz.  C12,  H10,  O10. 


ASSIMILATION.  193 

have  seen  that  many  plants  must,  and  all  may,  imbibe  the  whole  or 
a  part  of  their  food  directly  from  the  air  into  their  leaves  (330). 
All  leafy  plants  evidently  obtain  a  part  of  their  carbonic  acid  in  this 
way.  It  is  accordingly  found,  that  when  a  current  of  carbonic  acid 
is  made  slowly  to  traverse  a  glass  globe  containing  a  leafy  plant  ex- 
posed to  full  sunshine,  some  carbonic  acid  disappears,  and  an  equal 
bulk  of  oxygen  gas  supplies  its  place.  Now,  since  carbonic  acid  gas 
contains  just  its  own  bulk  of  oxygen,  it  is  evident  that  what  has  thus 
been  decomposed  in  the  leaves  has  returned  all  its  oxygen  to  the 
air.  Plants  take  carbonic  acid  from  the  atmosphere,  therefore 
(directly  or  indirectly)  ;  they  retain  its  carbon ;  they  give  back  its 
oxygen.* 

349.  But  cellulose,  being  the  final,  insoluble  product  of  vegetation 
appropriated  as  tissue,  can  hardly  be  directly  formed  in  the  first  in- 
stance. The  substances  from  which  it  must  originate,  and  which 
actually  abound  in  the  elaborated  sap,  are  Dextrine  or  Vegetable 
Mucilage  (79,  83),  Sugar  (80),  &c  The  first  of  these  is  probably 
directly  produced  in  assimilation.  Its  chemical  composition  is  the 
same  as  that  of  pure  cellulose :  it  consists,  not  only  of  the  same 
three  elements,  but  of  the  same  elements  in  exactly  the  same  pro- 
portion. Dextrine,  vegetable  mucilage,  &c.  are  the  primary,  as  yet 
unappropriated  materials  of  vegetable  tissue,  or  unsolidified  cellu- 
lose, and  their  production  from  the  crude  sap  is  attended  with  the 
evolution  of  the  oxygen  which  was  contained  in  the  carbonic  acid 
of  the  plant's  food,  as  already  stated.  Nor  would  the  result  in  any 
respect  be  altered  if  Starch  were  directly  produced.  This  substance 
is  merely  dextrine,  which,  instead  of  being  immediately  appropriated 
in  growth,  is  condensed  into  solid  grains,  and  in  that  compact  and 

*  At  least,  the  result  is  as  if  the  oxygen  exhaled  were  all  thus  detached  from 
the  carhon  of  the  carbonic  acid.  Just  this  amount  is  liberated,  and  the  facts 
obviously  point  to  the  carbonic  acid  as  its  real  source.  But,  on  the  other  hand, 
it  appears  unlikely  that  a  substance  which  holds  oxygen  with  such  strong  affinity 
as  carbon  should  yield  the  whole  of  it  under  these  circumstances  :  and  water  is 
certainly  decomposed,  with  the  evolution  of  oxygen,  in  the  formation  of  a  class 
of  vegetable  products  soon  to  be  mentioned  ;  besides,  Edwards  and  Colin  have 
shown  that  water  is  directly  decomposed  during  germination.  Still,  as  no  one 
supposes  that  the  residue  after  the  liberation  of  oxygen  is  carbon  and  water, 
but  only  the  three  elements  in  the  proportions  which  would  constitute  them,  it 
amounts  to  nearly  the  same  thing  whether  we  say  that  the  oxygen  of  the  carbonic 
acid,  or  an  amount  of  oxygen  equivalent  to  that  of  the  carbonic  acid,  derived  partly 
from  it  and  partly  from  the  water,  is  liberated  in  such  cases. 

17 


194  THE    FOOD    AND    NUTRITION    OF    PLANTS. 

temporarily  insoluble  form  accumulated  as  the  ready  prepared  ma- 
terials of  future  growth  (82).  Notwithstanding  the  difference  in 
their  properties  and  chemical  reactions,  these  and  other  general 
ternary  products  (79)  are  strictly  isomeric ;  that  is,  they  consist  of 
the  same  elements,  combined  in  the  same  proportions ;  and  physi- 
ologically they  are  merely  different  states  of  one  and  the  same  thing. 
Dextrine  is  the  most  soluble  state,  and  is  probably  that  originally 
formed  in  assimilation  in  the  foliage :  starch,  amyloid  (83),  &c.  are 
temporarily  solidified  states ;  and  cellulose  is  the  ultimate  and  usu- 
ally permanent  insoluble  condition.  Accordingly,  whenever  the  ma- 
terials of  growth  are  supplied  from  accumulations  of  nourishment, 
as  especially  from  the  seed  in  germination  (123-125),  from  fleshy 
roots  (145),  rootstocks,  tubers,  &c.  (188-194),  the  starch  or  its 
equivalent  is  dissolved  in  the  sap,  being  spontaneously  reconverted 
into  dextrine  and  sugar,  and  attracted  in  a  liquid  state  into  the 
growing  parts,  where,  transformed  into  cellulose,  it  becomes  a  por- 
tion of  the  permanent  vegetable  fabric. 

350.  If,  however,  we  suppose  sugar  to  be  a  direct  product  of  the 
assimilation  of  carbonic  acid  and  water,  the  amount  of  oxygen  gas 
exhaled  will  be  just  the  same  as  before.  For  this  has  the  same 
elementary  composition  as  dextrine,  starch,  and  cellulose,  with  the 
addition  of  one  or  two  equivalents  of  water  according  to  the  kind.* 
And  when  formed  as  a  transformation  of  dextrine,  then  the  latter 
has  only  to  appropriate  some  water.  In  the  origination  of  all  these 
products,  therefore,  the  same  quantity  of  carbonic  acid  is  consumed, 
and  all  its  oxygen  restored  to  the  air.f     It  is  more  and  more  evident, 


*  The  formula  for  cane-sugar  is  Ci2,  Hn,  On  ;  for  grape-sugar,  Ci2,  Hi2,  O12. 

t  Since  all  these  neutral  ternary  substances  are  identical,  or  nearly  so,  in  ele- 
mentary composition,  and  since,  with  the  same  amount  of  carbon,  derived  from 
the  decomposition  of  carbonic  acid,  the  plant  can  form  them  all,  it  will  no  longer 
appear  surprising  that  they  should  be  so  readily  convertible  into  each  other  in 
the  living  plant,  and  even  in  the  hands  of  the  chemist.  But  the  chemistry  of 
organic  nature  exceeds  the  resources  of  science,  and  constantly  produces  trans- 
formations which  the  chemist  in  his  laboratory  is  unable  to  effect.  The  latter 
can  change  starch  into  dextrine,  and  dextrine  into  sugar ;  but  he  cannot  reverse 
the  process,  and  convert  sugar  into  dextrine,  or  dextrine  into  starch.  In  the 
plant,  however,  all  these  various  transformations  are  continually  taking  place. 
Thus,  the  starch  deposited  in  the  seed  of  the  Sugar-cane,  Indian  Corn,  &c.  is 
changed  into  sugar  in  germination  ;  and  the  sugar  which  fills  the  tissue  of  the 
stem  at  the  time  of  flowering  is  rapidly  carried  into  the  flowers,  where  a  portion 
is  transformed  into  starch  and  again  deposited  in  the  newly-formed  seeds.     And 


ASSIMILATION.  195 

therefore,  that,  by  just  so  much  as  plants  grow,  they  take  carbonic 
acid  from  the  air,  they  retain  its  carbon,  and  return  its  oxygen. 

351.  In  the  production  of  that  modification  of  cellulose  called 
Lignine  (42),  which  abounds  in  wood  (if  this  be  really  a  simple 
product,  and  not  a  mixture),  not  only  must  a  larger  amount  of  car- 
bonic acid  be  decomposed,  but  a  small  portion  of  water  also,  Avith 
the  liberation  of  its  oxygen.  For  the  composition  attributed  to  it 
shows  that  it  contains  less  oxygen  than  would  suffice  to  convert  its 
hydrogen  into  water.* 

352.  The  whole  class  of  fatty  substances,  including  the  Oils,  Wax, 
Chlorophyll  (84,  88,  92),  &c,  contain,  some  of  them  no  oxygen  at 
all  (such  as  caoutchouc  and  Pine-oil),  and  all  of  them  less  oxygen 
than  is  requisite  to  convert  their  hydrogen  into  water.  In  their 
direct  formation,  if  this  be  supposed,  not  only  all  the  oxygen  of  the 
carbonic  acid  has  been  given  out,  but  also  a  portion  belonging  to  the 
water.  If  formed  by  a  further  deoxidation  of  neutral  ternary  pro- 
ducts, the  same  result  is  attained  as  respects  the  liberation  of  oxy- 
gen gas,  but  by  two  or  more  steps  instead  of  one.  The  Resins, 
doubtless,  are  not  direct  vegetable  products,  but  originate  from  the 
alternation  and  partial  oxidation  of  the  essential  oils.  Balsams, 
which  exude  from  the  bark  of  certain  plants,  are  natural  solutions  of 
resins  in  their  essential  oils,  as  rosin,  or  Pine-resin,  in  the  oil  of  tur- 
pentine. 

353.  An  opposite  class,  the  Vegetable  Acids  (8G),  contain  more 
oxygen  than  is  necessary  for  the  conversion  of  their  hydrogen  into 
water,  but  less  than  the-  amount  which  exists  in  carbonic  acid  and 
water.  Indeed,  the  most  general  vegetable  acid,  the  oxalic  (which 
may  be  formed  artificially  by  the  action  of  nitric  acid  on  starch), 
has  no  hydrogen,  except  in  the  atom  of  water  that  is  connected  with 
it.     Acids  are  sometimes  formed  in  the  leaves,  as  in  the  Sorrel,  the 


although  the  chemist  is  unable  to  transform  starch,  sugar,  &c.  into  cellulose,  yet 
he  readily  effects  the  opposite  change,  by  reconverting  woody  fibre,  &c.  (under 
the  influence  of  sulphuric  acid)  into  dextrine  and  sugar.  The  plant  does  the 
same  thing  in  the  ripening  of  fruits,  during  which  a  portion  of  tissue  is  often 
transformed  into  sugar.  Starch-grains  and  cellulose  can  never  be  formed  arti- 
ficially, because  they  are  not  merely  organizable  matter,  but  have  an  organic 
structure. 

*  According  to  Payen,  lignine,  separated  as  much  as  possible  from  cellulose, 
consists  of  Carbon  53.8,  Hydrogen  6.0,  and  Oxygen  40.2  per  cent,  =  C35,  H21, 
Oso. 


196  THE    FOOD    AND    NUTRITION    OF    PLANTS. 

Grape-vine,  &c,  but  usually  in  the  fruit.  If  produced  directly  from 
the  sap,  as  they  may  be  in  acid  leaves,  only  a  part  of  the  oxygen  in 
the  carbonic  acid  which  contributes  to  their  formation  would  be  ex- 
haled. But  if  formed  from  sugar,  or  any  other  of  the  general  pro- 
ducts of  the  proper  juice,  the  absorption  of  a  portion  of  oxygen  from 
the  air  would  be  required  for  the  conversion ;  and  this  absorption 
takes  place  (at  least  in  some  cases)  when  fruits  acquire  their  acidity. 
Even  their  formation  by  the  plant,  therefore,  is  attended  by  the  lib- 
eration of  oxygen  gas,  though  in  less  quantity  than  in  ordinary  vege- 
tation. 

354.  There  is  still  another  class  of  vegetable  products  of  uni- 
versal occurrence,  and,  although  comparatively  small  in  quantity  in 
plants,  yet  of  as  high  importance  as  those  which  constitute  their 
permanent  fabric ;  namely,  the  neutral  quaternary  organic  com- 
pounds, of  which  nitrogen  is  a  constituent  (79).  These,  also,  are 
mutually  convertible  bodies,  related  to  each  other  as  dextrine  and 
sugar  are  to  starch  and  cellulose,  and  playing  the  same  part  in  the 
animal  economy  that  the  neutral  ternary  products  do  in  the  vege- 
table, i.  e.  forming  the  fabric  of  animals.  The  basis  or  type  of 
these  azotized  products  has  received  the  name  of  Proteine  (27)  : 
hence  they  are  sometimes  collectively  called  proteine  compounds. 
In  their  production  from  the  plant's  food,  the  ammonia,  or  other 
azotized  matter  it  contains,  plays  an  essential  part ;  and  oxygen  gas 
is  restored  to  the  air  from  the  decomposition  of  all  the  carbonic  acid 
concerned  and  of  a  part  of  the  water.* 

855.  In  living  cells  the  proteine  forms  the  protoplasm,  or  vitally 
active  lining,  which  may  be  said  to  give  origin  to  the  vegetable 
structure,  since  the  cellulose  is  deposited  under  its  influence  to 
form  the  permanent  walls  or  fabric  of  the  cells,  as  has  already  been 
explained  (26-3G).     When  the  cells  have  completed  their  growth 


*  The  chemical  changes  have  been  tabulated  thus  :  — 

The  materials  : 

From  which  are  formed  the  product : 

C.    H. 

N.     0. 

C.     H. 

N.     0. 

74  of  Water,                      74 

74 

1  of  Proteine,       48     36 

6      14 

94  of  Carbonic  acid,  94 

188 

4  of  Cellulose,      48     40 

40 

2  of  Carbonate  of 

212  of  Oxygen  lib- 

ammonia,               2       2 

6       4 

crated, 

212 

96     76       6  266  96     76       6    266 

Besides,  proteine  cither  contains  or  is  naturally  combined  with  a  small  quan- 
tity of  sulphur  and  phosphorus  (10). 


ASSIMILATION.  197 

and  transformation,  the  protoplasm  abandons  them,  the  portion  which 
is  not  decomposed  being  constantly  attracted  onwards  into  forming 
and  growing  parts,  where  it  incites  new  development.  For  this 
azotized  matter  has  the  remarkable  peculiarity  of  inducing  chemical 
changes  in  other  organic  products,  especially  the  neutral  ternary 
bodies,  causing  one  kind  to  be  transformed  into  another,  or  even  the 
decomposition  of  a  part  into  alcohol,  acetic  acid,  and  finally  into 
carbonic  acid  and  water  (as  in  germination,  &c),  —  itself  remaining 
the  while  essentially  unaltered. 

356.  The  constant  attraction  of  the  protoplasm  from  the  com- 
pleted into  the  forming  parts  of  the  plants  explains  how  it  is,  that 
so  small  a  percentage  of  azotized  matter  should  be  capable  of 
playing  such  an  all-important  part  in  the  vegetable  economy.  It 
does  its  work  with  little  loss  of  material,  and  no  portion  of  it  is  fixed 
in  the  tissues.  At  least,  the  little  that  remains  in  old  parts  is  capa- 
ble of  being  washed  out,  showing  that  it  forms  no  integral  part  of 
the  fabric.  This  explains  why  the  heartwood  of  trees  yields  barely 
a  trace  of  nitrogen,  while  the  sap-wood  yields  an  appreciable  amount, 
and  the  cambium-layer  and  all  parts  of  recent  formation,  such  as  the 
buds,  young  shoots,  and  rootlets,  always  contain  a  notable  proportion 
of  it.  This  gives  the  reason,  also,  why  sap-wood  is  so  liable  to  decay 
(induced  by  the  proteine),  the  more  so  in  proportion  to  its  newness 
and  the  quantity  of  sap  it  contains,  while  the  completed  heart-wood 
is  so  durable.  The  azotized  matter  rapidly  diminishes  in  the  stem 
and  herbage  during  flowering,  while  it  accumulates  in  the  forming 
fruit,  and  is  finally  condensed  in  the  seeds  (which  have  a  larger  per- 
centage than  any  other  organ),  ready  to  subserve  the  same  office  in 
the  development  of  the  embryo  plant  it  contains.* 

357.  When  wheat-flour,  kneaded  into  dough,  is  subjected  to  the 
prolonged  action  of  water,  the  starch  is  washed  away,  and  a  tena- 
cious, elastic  residue,  the  Gluten  of  the  flour,  which  gives  it  the 
capability  of  being  raised,  remains.  This  contains  nearly  all  the 
proteine  compounds  of  the  seed,  mixed  with  some  fatty  matters 
(which  may  be  removed  by  alcohol  and  ether)  and  with  a  little 
cellulose.  The  azotized  products  constitute  from  eight  to  thirty 
per  cent  of  the  weight  of  wheat-flour :  the  proportion  varies  greatly 

*  The  cotyledons  of  peas  and  beans,  according  to  Mr.  Rigg,  contain  from 
100  to  140  parts,  and  the  plumule  about  200  parts,  of  nitrogen,  to  1,000  parts  of 
carbon. 

17* 


198  THE    FOOD    AND    NUTRITION    OF   PLANTS. 

under  different  circumstances,  but  it  is  always  largest  when  the  soil 
is  well  supplied  with  manures  that  abound  in  nitrogen.  The  gluten 
of  wheat  is  a  mixture  of  four  isomeric  quaternary  products,  distin- 
guished by  chemists  under  the  names  Fibrine  (identical  in  nature 
with  that  which  forms  the  muscles  of  animals),  Albumen  (of  the  same 
nature  as  animal  albumen),  Caseine  (identical  with  the  curd  of  milk), 
and  Glutine.  In  beans  and  all  kinds  of  pulse,  or  seeds  of  Legu- 
minous plants,  the  azotized  matter  principally  occurs  in  the  form 
of  Legumine,  which  is  nearly  intermediate  in  character  between  albu- 
men and  caseine. 

358.  Comparing  now  these  principal  products  of  assimilation  in 
plants  with  the  inorganic  materials  from  which  they  must  needs  be 
formed,  it  may  clearly  be  perceived  that  the  principal  result  of  vege- 
tation, as  concerns  the  atmosphere,  from  which  plants  draw  their 
food,  consists  in  the  withdrawal  of  water,  of  a  little  ammonia,  and  of 
a  large  proportion  of  carbonic  acid,  and  of  the  restoration  of  oxygen. 
The  latter  is  a  constant  effect  of  vegetation  and  the  measure  of  its 
amount.  As  respects  the  fabric  of  the  plant,  the  sole  consequences 
of  its  formation  upon  the  air  are  the  withdrawal  of  a  small  quantity 
of  water,  and  of  a  large  amount  of  carbonic  acid  gas,  and  the  resto- 
ration of  the  oxygen  of  the  latter.  In  the  formation  of  its  azotized 
materials,  a  portion  of  ammonia  or  of  some  equn-alent  compound  of 
nitrogen  is  also  withdrawn.  It  is  time,  indeed,  that  leaves  decom- 
pose carbonic  acid  only  in  daylight ;  and  that  they  sometimes  give  a 
quantity  of  carbonic  acid  to  the  air  in  the  night,  especially  when 
vegetation  languishes,  or  even  take  from  it  a  little  oxygen.  But 
this  does  not  affect  the  general  result,  nor  require  any  qualification 
of  the  general  statement.  The  work  simply  ceases  when  light  is 
withdrawn.  The  plant  is  then  merely  in  a  passive  state.  Yet, 
whenever  exhalation  from  the  leaves  slowly  continues  in  darkness, 
the  carbonic  acid  Avhich  the  water  holds  necessarily  flies  off  with  it, 
during  the  interruption  to  vegetation,  into  the  atmosphere  from 
which  the  plant  took  it.  So  much  of  the  crude  sap,  or  raw  mate- 
rial, merely  runs  to  waste.  Furthermore,  it  must  be  remembered 
that  the  decomposition  of  carbonic  acid  in  vegetation  is  in  direct  op- 
position to  ordinary  chemical  affinity ;  or,  in  other  words,  that  all 
organized  matter  is  in  a  state  corresponding  to  that  of  unstable 
equilibrium.  Consequently,  when  light  is  withdrawn,  ordinary 
chemical  forces  may  perhaps  to  some  extent  resume  their  sway,  the 
oxygen  of  the  air  combine  with  some  of  the  newly  deposited  carbon 


INFLUENCE    OF  VEGETATION    ON    THE   ATMOSPHERE.  199 

to  reproduce  a  little  carbonic  acid,  and  thus  demolish  a  portion  of 
the  rising  vegetable  structure  which  the  setting  sun  left,  as  it  were, 
in  an  unfinished  or  unstable  state.  This  is  what  actually  takes  place 
in  a  dead  plant  at  all  times,  and  whenever  an  herb  is  kept  in  pro- 
longed darkness  ;  chemical  forces,  exerting  their  power  uncontrolled, 
demolish  the  whole  vegetable  fabric,  beginning  with  the  chlorophyll 
(as  we  observe  in  blanching  Celery),  and  at  length  resolve  it  into 
the  carbonic  acid  and  water  from  which  it  was  formed.  But  this 
must  all  be  placed  to  the  account  of  decomposing,  not  of  groioing 
vegetation  ;  and  even  if  it  were  a  universal  phenomenon,  which  is 
by  no  means  the  case,*  would  not  affect  the  general  statement,  that, 
by  so  much  as  plants  groiv,  they  decompose  carbonic  acid  and  give 
its  oxygen  to  the  air  ;  or,  in  other  words,  purify  the  air. 

359.  Every  six  pounds  of  carbon  in  existing  plants  have  withdrawn 
twenty-two  pounds  of  carbonic  acid  gas  from  the  atmosphere,  and 
replaced  it  with  sixteen  pounds  of  oxygen  gas,  occupying  the  same 
bulk.  To  form  some  general  conception  of  the  extent  of  the  influ- 
ence of  vegetation  upon  the  air  we  breathe,  therefore,  we  should 
compute  the  quantity  of  carbon,  or  charcoal,  that  is  contained  in  the 


*  It  is  stated  that  many  ordinary  plants,  when  in  full  health  and  vigorous 
vegetation,  impart  no  carbonic  acid  to  the  air  during  the  night.  —  See  Pepys,  in 
Philosophical  Transactions,  for  1 843.  —  Plants  deteriorate  the  air  only  in  their 
decay,  and  in  peculiar  processes,  distinct  from  vegetation  and  directly  the  re- 
verse of  assimilation  ;  as  in  germination,  for  instance,  where  the  proteine  in- 
duces the  decomposition  of  a  portion  of  the  store  of  assimilated  matter,  in  order 
that  the  rest  may  he  brought  into  a  serviceable  condition.  The  evolution  of 
carbonic  acid  by  plants,  therefore,  when  it  occurs,  is  no  part  of  vegetation.  And 
it  is  by  a  false  analogy  that  this  loss  which  plants  sustain  in  the  night  has  been 
dignified  with  the  name  of  vegetable  respiration,  and  vegetables  said  to  vitiate  the 
atmosphere,  just  like  animals,  by  their  respiration,  while  they  purify  it  by  their 
digestion.  If,  indeed,  this  were  a  constant  function,  in  any  way  contributing  to 
maintain  the  life  and  health  of  the  plant,  it  might  be  properly  enough  compared 
with  the  respiration  of  animals,  which  is  itself  a  decomposing  operation.  But 
thus  is  not  the  case.  And  herein  is  a  characteristic  difference  between  vegetables 
and  animals :  the  tissues  of  the  latter  require  constant  interstitial  renewal  by 
nutrition,  new  particles  replacing  the  old,  which  are  removed  and  restored  to  the 
mineral  world  by  respiration :  while  in  plants  there  is  no  such  renewal,  but  the 
fabric,  once  completed,  remains  unchanged,  ceases  to  be  nourished,  and  conse- 
quently soon  loses  its  vitality ;  while  new  parts  are  continually  formed  farther 
on  to  take  their  places,  to  be  in  turn  abandoned.  Plants,  therefore,  having  no 
decomposition  and  recomposition  of  any  completed  fabric,  cannot  properly  be 
said  to  have  the  function  of  respiration. 


200  THE   FOOD    AND    NUTRITION    OF    PLANTS. 

forests  and  herbage  of  the  world,  and  add  to  the  estimate  all  that 
exists  in  the  soil,  as  vegetable  mould,  peat,  and  in  other  forms ;  all 
that  is  locked  up  in  the  vast  deposits  of  coal  (the  product  of  the 
vegetation  of  bygone  ages) ;  and,  finally,  all  that  pertains  to  the 
whole  existent  animal  kingdom ;  —  and  we  shall  have  the  aggregate 
amount  of  a  single,  though  the  largest,  element  which  vegetation  has 
withdrawn  from  the  atmosphere.  By  multiplying  this  vast  amount 
of  carbon  by  sixteen,  and  dividing  it  by  six,  we  obtain  an  expression 
of  the  number  of  pounds  of  oxygen  gas  that  have  in  this  process 
been  supplied  to  the  atmosphere. 

3 GO.  Rightly  to  understand  the  object  and  consequences  of  this 
immense  operation,  which  has  been  going  on  ever  since  vegetation 
began,  it  should  be  noted,  that,  so  far  as  Ave  know,  vegetation  is 
the  only  operation  in  nature  which  gives  to  the  air  free  oxygen  gas, 
that  indispensable  requisite  to  animal  life.  There  is  no  other  pro- 
vision for  maintaining  the  supply.  The  prevailing  chemical  ten- 
dencies, on  the  contrary,  take  oxygen  from  the  air.  Few  of  the 
materials  of  the  earth's  crust  are  saturated  with  it ;  some  of  them 
still  absorb  a  portion  from  the  air  in  the  changes  they  undergo ; 
and  none  of  them  give  it  back  in  the  free  state  in  which  they  took 
it,  —  in  a  state  to  support  animal  life,  —  by  any  known  natural 
process,  at  least  upon  any  considerable  scale.  Animals  all  con- 
sume oxygen  at  every  moment  of  their  life,  giving  to  the  air  carbonic 
acid  in  its  room ;  and  when  dead,  their  bodies  consume  a  further  por- 
tion in  decomposition.  Decomposing  vegetable  matter  produces  the 
same  result.  Its  carbon,  taking  oxygen  from  the  air,  is  likewise 
restored  in  the  form  of  carbonic  acid.  Combustion,  as  in  burning 
our  fuel,  amounts  to  precisely  the  same  thing ;  it  is  merely  rapid 
decay.  The  carbon  which  the  trees  of  the  forest  have  been  for 
centuries  gathering  from  the  air,  their  prostrate  decaying  trunks 
may  almost  as  slowly  restore  to  the  air,  in  the  original  form  of 
carbonic  acid.  But  if  set  on  fire,  the  same  result  may  be  accom- 
plished in  a  day.  All  these  causes  conspire  to  rob  the  air  of  its 
life-sustaining  oxygen.  The  original  supply  is  indeed  so  vast,  that, 
were  there  no  natural  compensation,  centuries  upon  centuries  would 
elapse  before  the  amount  of  oxygen  could  be  so  much  reduced,  or 
that  of  carbonic  acid  increased,  as  to  affect  the  existence  of  the 
present  races  of  animals.  But  such  a  period  would  eventually 
arrive,  were  there  no  natural  provision  for  the  decomposition  of  the 
carbonic  acid  constantly  poured   into  the   air  from  these   various 


RELATIONS    OF   THE    VEGETABLE    AND    ANIMAL    KINGDOMS.    201 

sources,  and  for  the  restoration  of  its  oxygen.  The  needful  com- 
pensation is  found  in  the  vegetable  kingdom.  While  animals  con- 
sume the  oxygen  of  the  air,  and  give  back  carbonic  acid  which  is 
injurious  to  their  life,  this  carbonic  acid  is  the  principal  element  of 
the  food  of  vegetables,  is  consumed  and  decomposed  by  them,  and 
its  oxygen  restored  for  the  use  of  animals.  Hence  the  perfect  adap- 
tation of  the  two  great  kingdoms  of  living  beings  to  each  other ;  — 
each  removing  from  the  atmosphere  what  would  be  noxious  to  the 
other;  —  each  yielding  to  the  atmosphere  what  is  essential  to  the 
continued  existence  of  the  other.* 

3G1.  The  relations  of  simple  vegetation,  under  this  aspect,  to  the 
mineral  kingdom  on  the  one  hand,  and  the  animal  kingdom  on  the 
other,  are  simply  set  forth  in  the  first  part  of  the  diagram  placed  at 
the  close  of  this  chapter. 

3G2.  But,  besides  this  remotely  essential  office  in  purifying  the 
air,  the  vegetable  kingdom  renders  to  the  animal  another  service 
so  immediate,  that  its  failure  for  a  single  year  would  nearly  depop- 
ulate the  earth ;  namely,  in  providing  the  necessary  food  for  the 
whole  animal  kingdom.  It  is  under  this  view  that  the  great  office 
of  vegetation  in  the  general  economy  of  the  world  is  to  be  contem- 
plated. Plants  are  the  sole  producers  of  nourishment.  They  alone 
transform  mineral,  chiefly  atmospheric  materials,  they  condense  air, 
into  organized  matter.  While  they  thus  produce  upon  a  vast  scale, 
they  consume  or  destroy  comparatively  little;  and  this  never  in 
proper  vegetation,  but  in  some  special  processes  hereafter  to  be  con- 
sidered (370).  Often  when  they  appear  to  consume  their  own  pro- 
ducts, they  only  transform  and  transfer  them,  as  when  the  starch 
of  the  potato  is  converted  into  new  shoots  and  foliage. 

363.  Animals  consume  what  vegetables  produce.  They  them- 
selves produce  nothing  directly  from  the  mineral  world.  The 
herbivorous  animals  take  from  vegetables  the  organized  matter 
which  they  have  produced ;  —  a  part  of  it  they  consume,  and  in 
respiration   restore   the   materials    to  the  atmosphere,  from  which 

*  It  is  plain,  however,  that,  while  the  animal  kingdom  is  entirely  dependent 
on  the  vegetable,  the  latter  is  independent  of  the  former,  and  might  have 
existed  alone.  The  decaying  races  of  plants,  giving  back  their  carbon  to  the 
air  and  to  the  soil  by  decay,  would  furnish  food  for  their  successors.  And  since 
all  the  carbonic  acid  which  animals  render  to  the  air  in  respiration  they  have 
derived  from  their  vegetable  food,  this  would  in  time  have  found  its  way  back  to 
the  air,  for  the  use  of  new  generations  of  plants,  without  the  intervention  of 
animals.     At  most,  they  merely  expedite  its  return. 


202  THE    FOOD    AND    NUTRITION    OF   PLANTS. 

plants  derived  them,  in  the  veiy  form  in  which  they  were  taken, 
namely,  as  carbonic  acid  and  water.  The  portion  they  accumulate 
in  their  tissues  constitutes  the  food  of  carnivorous  animals  ;  who 
consume  and  return  to  the  air  the  greater  part  during  life,  and  the 
remainder  in  decay  after  death.  The  atmosphere,  therefore,  out  of 
which  plants  create  nourishment,  and  to  which  animals  as  they  con- 
sume return  it,  forms  the  necessary  link  between  the  animal  and 
vegetable  kingdoms,  and  completes  the  great  cycle  of  organic  exist- 
ence. Organized  matter  passes  through  various  stages  in  vege- 
tables, through  others  in  the  herbivorous  animals,  and  undergoes  its 
final  transformations  in  the  carnivorous  animals.  Portions  are  con- 
sumed at  every  stage,  and  restored  to  the  mineral  kingdom,  to  which 
the  whole,  having  accomplished  its  revolution,  finally  returns. 

364.  Moreover,  plants  not  only  furnish  all  the  materials  of  the 
animal  fabric,  but  furnish  each  principal  constituent  ready  formed, 
so  that  the  animal  has  only  to  appropriate  it.  The  food  of  animals 
is  of  two  kinds;  —  1.  that  which  serves  to  support  respiration  and 
maintain  the  animal  heat ;  2.  that  which  is  capable  of  forming  a 
portion  of  the  animal  fabric,  of  its  flesh  and  bones.  The  ternary 
vegetable  products  furnish  the  first,  in  the  form  of  sugar,  vegetable 
jelly,  stai*ch,  oil,  &c,  and  even  cellulose ;  substances  which,  contain- 
ing no  nitrogen,  cannot  form  an  integral  part  of  the  animal  frame, 
but,  conveyed  into  the  blood,  are  decomposed  in  respiration ;  the 
carbon  and  the  excess  of  hydrogen  combining  with  the  oxygen  of 
the  air,  to  which  they  are  restored  in  the  form  of  carbonic  acid  and 
water.  Any  portion  not  required  by  the  immediate  demands  of  res- 
piration is  stored  in  the  tissues  in  the  form  of  fat,  (which  the  animal 
may  either  accumulate  directly  from  the  oily  and  waxy  matters  in 
iis  vegetable  food,  or  produce  by  an  alteration  of  the  starch  and 
sugar,)  as  a  provision  for  future  use  :  a  deficiency  of  such  materials 
subjects  the  tissues  themselves,  or  the  proper  supporting  food,  to  im- 
mediate decomposition  in  respiration.  The  quaternary  or  azotized 
products  furnish  the  proper  materials  of  the  animal  frame,  the 
fibrine,  caseine,  albumen,  &c.  being  directly  appropriated  from  the 
vegetable  food  to  form  the  blood,  muscles,  &c. ;  while  a  slight  trans- 
formation of  them  gives  origin  to  gelatine,  of  which  the  sinews,  carti- 
lages, and  the  organic  part  of  the  bones,  consist.  The  earthy  por- 
tion of  the  bones,  the  iron  in  the  blood,  and  the  saline  ingredients 
of  the  animal  body,  are  drawn  from  the  earthy  constituents  (336)  of 
the  plants  upon  which  the  animal  feeds.     The  animal  merely  ap- 


RELATIONS    OF    THE    THREE    KINGDOMS    OF   NATURE. 


203 


propriates  and  accumulates  these  already  organizable  materials, 
changing  them,  it  may  be,  little  by  little,  as  he  destroys  them,  but 
rendering  them  all  back  (those  of  the  first  class  through  the  lungs, 
of  the  second  through  the  kidneys)  finally  to  the  earth  and  air,  from 
which,  and  in  the  condition  in  which,  the  vegetable  took  them. 

865.  The  general  relations  of  vegetation  to  the  mineral  and  ani- 
mal kingdoms  are  exhibited  in  the  subjoined  diagram. 


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204  FLOWERING   AND   ITS    CONSEQUENCES. 

CHAPTER     VII. 

OP    FLOWERING   AND   ITS   CONSEQUENCES. 

366.  Plants  have  thus  far  heen  considered  only  as  respects 
their  Organs  of  Vegetation,  —  those  which  essentially  constitute 
the  vegetable  being,  by  which  it  grows,  deriving  its  support  from 
the  surrounding  air  and  soil,  and  converting  these  inorganic  mate- 
rials into  its  own  organized  substance.  As  every  additional  supply 
of  nourishment  furnishes  materials  for  the  development  of  new 
branches,  roots,  and  leaves,  thus  multiplying  both  those  organs  which 
receive  food  and  those  which  assimilate  it,  it  would  seem  that,  apart 
from  accidents,  the  increase  and  extension  of  plants  would  be  limited 
only  by  the  failure  of  an  adequate  supply  of  nourishment.  After  a 
certain  period,  however,  varying  in  different  species,  but  nearly  con- 
stant in  each,  a  change  ensues,  which  controls  this  otherwise  indefi- 
nite extent  of  the  branches.  A  portion  of  the  buds,  instead  of  elon- 
gating into  branches,  are  developed  in  the  form  of  Flowers  ;  and 
nourishment  which  would  otherwise  contribute  to  the  general  in- 
crease of  the  plant,  is  devoted  to  their  production,  and  to  the  matu- 
ration of  the  fruit  and  seeds. 

367.  Flowering  an  Exhaustive  Process.    Plants  begin  to  bear  flowers 

at  a  nearly  determinate  period  for  each  species  ;  which  is  dependent 
partly  upon  constitutional  causes,  and  partly  upon  the  requisite  sup- 
ply of  nutritive  matter  in  their  system.  For,  since  the  flower  and 
fruit  draw  largely  upon  the  powers  and  nourishment  of  the  plant, 
while  they  yield  nothing  in  return,  fructification  is  an  exhaustive 
process,  and  a  due  accumulation  of  food  is  requisite  to  sustain  it.* 

*  "When  the  branch  of  a  fruit-tree,  which  is  sterile  or  does  not  perfect  its  blos- 
soms, is  ringed  or  girdled  (by  the  removal  of  a  narrow  ring  of  bark),  the  elab- 
orated juices,  being  arrested  in  their  downward  course,  are  accumulated  in  the 
branch,  which  is  thus  enabled  to  produce  fruit  abundantly ;  while  the  shoots  that 
appear  below  the  ring,  being  fed  by  the  much  weaker  ascending  sap,  do  not 
blossom,  but  push  forth  into  leafy  branches.  So  the  flowers  of  most  trees  and 
shrubs  that  bear  large  or  fleshy  fruit  are  produced  from  lateral  buds,  resting 
directly  upon  the  wood  of  the  previous  year,  in  which  a  quantity  of  nutritive 
matter  is  deposited.  So,  also,  a  seedling  shoot,  which  would  not  flower  for 
several  years  if  left  to  itself,  blossoms  the  next  season  when  inserted  as  a  graft 
into  an  older  trunk,  from  whose  accumulated  stock  it  draws. 


FLOWERING   AN    EXHAUSTIVE    TROCESS.  205 

Annuals  flower  in  a  few  weeks  or  months  after  they  spring  from  the 
seed,  when  they  have  little  nourishment  stored  up  in  their  tissue ; 
and  their  lives  are  destroyed  by  the  process  (144)  :  biennials  flower 
after  a  longer  period,  rapidly  exhausting  the  nourishment  accumu- 
lated in  the  root  during  the  previous  season,  and  then  perishing 
(145)  ;  while  shrubs  and  trees  do  not  commence  flowering  until 
they  are  sufficiently  established  to  endure  it.  The  exhaustion  con- 
sequent upon  flowering,  however,  is  often  exhibited  in  fruit-trees, 
which,  after  producing  an  excessive  crop  (especially  of  late  fruits, 
such  as  apples),  sometimes  fail  to  bear  the  succeeding  year.  When 
the  crop  of  one  year  fails,  the  nourishment  which  it  would  have  ap- 
propriated accumulates,  and  the  tree  may  bear  more  abundantly  the 
following  season,  and  so  on  alternately  from  year  to  year. 

368.  The  actual  consumption  of  nourishment  in  flowering  may 
be  shown  in  a  variety  of  ways ;  as  by  the  rapid  disappearance  of 
the  farinaceous  or  saccharine  store  in  the  roots  of  the  Carrot,  Beet, 
&c.  when  they  begin  to  flower,  leaving  them  light,  dry,  and  empty ; 
and  by  the  rapid  diminution  of  the  sugar  in  the  stalks  of  the  Sugar- 
cane and  of  Maize  at  the  same  period.  The  stalks  are  therefore 
cut  for  making  sugar  just  before  the  flowers  expand,  when  they 
contain  the  greatest  amount  of  saccharine  matter. 

369.  The  consequences  of  this  exhaustion  upon  the  duration  of 
plants  are  further  illustrated  by  the  facility  with  which  annuals  may 
be  changed  into  biennials,  or  their  life  prolonged  indefinitely  by 
preventing  their  flowering ;  while  they  perish  whenever  they  bear 
flowers  and  seed,  whether  during  the  first  or  any  succeeding  year. 
Thus,  a  common  annual  Larkspur  has  given  rise  to  a  double-flowered 
variety  in  the  gardens,  which  bears  no  seed,  and  has  therefore  be- 
come a  perennial.  Cabbage-stumps,  which  are  planted  for  seed,  may 
be  made  to  bear  heads  the  second  year  by  destroying  the  flower- 
shoots  as  they  arise  ;  and  the  process  may  be  continued  from  year  to 
year,  thus  converting  a  biennial  into  a  kind  of  perennial  plant.  The 
effect  of  flowering  upon  the  longevity  of  the  individual  is  strikingly 
shown  by  the  Agave,  or  Century-plant,  —  so  called  because  it  flow- 
ers in  our  conservatories  only  after  the  lapse  of  a  hundred,  or  at 
least  a  great  number  of  years  ;  although,  in  its  native  sultry  climate, 
it  generally  flowers  when  five  or  six  years  old.  But  whenever  this 
occurs,  the  sweet  juice  with  which  it  is  filled  at  the  time  (which  by 
fermentation  forms  pulque,  the  inebriating  drink  of  the  Mexicans)  is 
consumed  at  a  rate  answering  to  the  astonishing  rapidity  with  which 

18 


206  FLOWERING   AND   ITS    CONSEQUENCES. 

its  huge  flower-stalk  shoots  forth  (24),  and  the  whole  plant  inevita- 
bly perishes  when  the  seeds  have  ripened.  So,  also,  the  Corypha, 
or  Talipot-tree,  a  magnificent  Oriental  Palm,  which  lives  to  a  great 
age  and  attains  an  imposing  altitude  (bearing  a  crown  of  leaves, 
each  blade  of  which  is  often  thirty  feet  in  circumference),  flowers 
only  once  ;  but  it  then  bears  an  enormous  number  of  blossoms,  suc- 
ceeded by  a  crop  of  nuts  sufficient  to  supply  a  large  district  with 
seed  ;  and  the  tree  perishes  from  the  exhaustion. 

370.  Flowering  and  fruiting,  then,  draw  largely  upon  the  plant's 
resources,  Avhile  they  give  back  nothing  in  return.  In  these  opera- 
tions, as  also  in  germination,  vegetables  act  as  true  consumers  (like 
animals,  363),  decomposing  their  own  products,  and  giving  back 
carbonic  acid  and  water  to  the  air,  instead  of  taking  these  materials 
from  the  air.  It  is  in  flowering  that  they  actually  consume  most. 
In  fruiting,  although  a  large  quantity  of  nourishment  is  taken  from 
the  plants,  this  is  mostly  accumulated  in  the  fruit  and  seed,  in  a  con- 
centrated form,  for  the  future  use  of  the  new  individual  in  the  seed. 

371.  The  real  consumption  of  nourishment  by  the  flower  is  shown 
by  the  action  of  flowers  upon  the  air,  so  different  from  that  of  leaves. 
"While  the  foliage  withdraws  carbonic  acid  from  the  air,  and  re- 
stores oxygen  (346,  358),  flowers  take  a  small  portion  of  oxygen 
from  the  air,  and  give  back  carbonic  acid.  "While  leaves,  therefore, 
purify  the  air  we  breathe,  flowers  contaminate  it ;  though,  of  course, 
only  to  a  degree  which  is  relatively  and  absolutely  insignificant. 
This  process  is  necessarily  attended  by  the 

372.  Evolution  Of  Heat.  When  carbon  is  consumed  as  fuel,  and 
by  the  oxygen  of  the  air  converted  into  carbonic  acid,  an  amount 
of  heat  is  evolved  directly  proportionate  to  the  quantity  of  carbon 
consumed,  or  of  carbonic  acid  produced.  Precisely  the  same 
amount  is  more  slowly  generated  during  the  gradual  decomposition 
of  the  same  quantity  of  vegetable  matter  by  decay,  —  a  heat  which 
is  employed  by  the  gardener  when  he  makes  hot-beds  of  tan,  decay- 
ing leaves,  and  manure,  —  or  by  the  breathing  of  animals,  which 
maintains  their  elevated  temperature  (364).  The  conversion  of  a 
given  amount  of  carbon  and  hydrogen  into  carbonic  acid  and  water, 
under  whatever  circumstances  it  may  take  place,  and  whether  slowly 
or  rapidly,  generates  in  all  cases  the  very  same  amount  of  heat. 
Now,  since  flowers  consume  carbon  and  produce  carbonic  acid,  acting 
in  this  respect  like  animals,  they  ought  to  evolve  heat  in  proportion 
to  that  consumption.     This,  in  fact,  they  do.     The  evolution  of  heat 


EVOLUTION    OF   HEAT.  207 

in  blossoming  was  first  observed  by  Lamarck,  about  seventy  years 
ago,  in  tbe  European  Arum,  which,  just  as  the  flowers  open,  "  grows 
hot,  as  if  it  were  about  to  burn."  It  was  afterwards  shown  by  Saus- 
sure  in  a  number  of  flowers,  such  as  those  of  the  Bignonia,  Gourd, 
and  Tuberose,  and  the  heat  was  shown  to  be  in  direct  proportion  to 
the  consumption  of  the  oxygen  of  the  air,  or,  in  other  words,  of  the 
carbon  of  the  plant.  The  increase  of  temperature,  in  these  cases, 
was  measured  by  common  instruments.  But  now  that  themio-elec- 
tric  apparatus  affords  the  means  of  measuring  variations  inappre- 
ciable by  the  most  delicate  thermometer,  the  heat  generated  by  an 
ordinary  cluster  of  blossoms  may  be  detected.  The  phenomenon  is 
most  striking  in  the  case  of  some  large  tropical  plants  of  the  Arum 
family,  where  an  immense  number  of  blossoms  are  crowded  together 
and  muffled  by  a  hooded  leaf,  or  spathe  (390),  which  confines  and  rever- 
berates the  heat.  In  some  of  these,  the  temperature  rises  at  times 
to  twenty  or  even  fifty  degrees  (Fahrenheit)  above  that  of  the  sur- 
rounding air.  This  increase  of  temperature  occurs  daily,  from  the 
time  the  flowers  open  until  they  fade,  but  is  most  striking  during  the 
shedding  of  the  pollen.  At  night,  the  temperature  falls  nearly  to 
that  of  the  surrounding  air ;  but  in  the  course  of  the  morning  the 
heat  comes  on,  as  it  were  like  a  paroxysm  of  fever,  attaining  the 
maximum,  day  after  day,  very  nearly  at  the  same  hour  of  the  after- 
noon, and  gradually  declining  toAvards  evening.  In  ordinary  cases, 
the  heat  of  flowering  is  more  than  counterbalanced  by  the  vaporiza- 
tion of  the  sap  and  the  absorption  of  solar  heat  by  the  foliage ;  so 
that  the  actual  temperature  of  a  leafy  plant  in  summer  is  lower  than 
that  of  the  atmosphere. 

373.  We  have  remarked  that  the  principal  consumption  takes 
place  in  the  flower ;  and  that  a  store  is  laid  up  in  the  fruit  and  seed. 
But  much  even  of  this  store  is  consumed  when  the  seed  germinates ; 
and  in  germination,  as  is  seen  in  the  malting  of  barley,  a  large 
amount  of  organic  matter  is  decomposed  into  carbonic  acid  and 
water,  and  a  proportionate  quantity  of  heat  is  evolved.  By  a  not 
veiy  violent  metaphor  it  may  be  said,  therefore,  that  the  fabled  Phoe- 
nix is  realized  in  the  Century-plant  (369),  which,  after  living  a  hun- 
dred years,  consumes  itself  in  producing  and  giving  life  to  its  off- 
spring, who  literally  rise  from  its  ashes. 

374.  Plants  need  a  Season  Of  Rest.  When  plants  are  in  luxuriant 
growth,  rapidly  pushing  forth  leafy  branches,  they  are  not  apt  to 
produce   flower-buds.     Our   fruit-trees,   in   very  moist   seasons,  or 


208  FLOWERING   AND   ITS    CONSEQUENCES. 

•when  cultivated  in  too  rich  a  soil,  often  grow  luxuriantly,  but  do  not 
blossom.  The  same  thing  is  observed  when  our  Northern  fruit-trees 
are  transported  into  tropical  climates.  On  the  other  hand,  -whatever 
checks  this  continuous  growth,  without  affecting  the  health  of  the 
individual,  causes  blossoms  to  appear  earlier  and  more  abundantly 
than  they  otherwise  would.  It  is  for  this  reason  that  transplanted 
fruit-trees  incline  to  blossom  the  first  season  after  their  removal, 
though  they  may  not  do  so  again  for  several  years.  A  state  of  com- 
parative rest  seems  needful  to  the  transformation  by  which  flowers 
are  formed.  It  is  in  autumn,  or  at  least  after  the  vigorous  vegeta- 
tion of  the  season  is  over,  that  our  trees  and  shrubs,  and  most  peren- 
nial herbs,  form  the  flower-buds  of  the  ensuing  year. 

375.  The  requisite  annual  season  of  repose,  which  in  temperate 
climates  is  attained  by  the  lowering  of  the  temperature  in  autumn  and 
winter,  is  scarcely  less  marked  in  many  tropical  countries,  where 
winter  is  unknown.  But  the  result  is  there  brought  about,  not  by 
cold,  but  by  heat  and  dryness.  The  Cape  of  Good  Hope,  the 
Canary  Islands,  and  the  southern  and  interior  parts  of  California, 
may  be  taken  as  illustrations.  In  the  Canaries,  the  growing  season 
is  from  November  to  March,  —  the  winter  of  the  northern  hemi- 
sphere ;  —  their  winter  also,  as  it  is  the  coolest  season,  the  mean 
temperature  being  06°  Fahr.  But  the  rains  fall  regularly,  and 
vegetation  is  active  ;  while  in  summer,  from  April  to  October,  it 
very  seldom  rains,  and  the  mean  temperature  is  as  high  as  73°. 
During  this  dry  season,  when  the  scorching  sun  reduces  the  soil 
nearly  to  the  dryness  and  consistence  of  brick,  ordinary  vegetation 
almost  completely  disappears  ;  and  the  Fig-Marigolds,  Euphorbias, 
and  other  succulent  plants,  which,  fitted  to  this  condition  of  things, 
alone  remain  green,  not  unaptly  represent  the  Firs  and  other  ever- 
greens of  high  northern  latitudes.  The  dry  heat  there  brings  about 
the  same  state  of  vegetable  repose  as  cold  with  us.  The  roots  and 
bulbs  then  lie  dormant  beneath  the  sunburnt  crust,  just  as  they  do 
in  our  frozen  soil.  "When  the  rainy  season  sets  in,  and  the  crust  is 
softened  by  moisture,  they  are  excited  into  growth  under  a  dimin- 
ished temperature,  just  as  with  us  by  heat ;  and  the  ready-formed 
flower-buds  are  suddenly  developed,  clothing  at  once  the  arid 
waste  with  a  profusion  of  blossoms  (194).  The  vegetation  of  such 
regions  consists  mainly  of  succulents,  which  are  able  to  live  through 
the  drought  and  exposure  ;  of  bulbous  plants,  which  run  through 
their  course  before  the  drought  becomes  severe,  then  lose  their 


THE    INFLORESCENCE.  209 

foliage,  while  the  bud  remains  quiescent,  safely  protected  under 
ground  until  the  rainy  season  returns  ;  and  of  annuals,  which  make 
their  whole  growth  in  a  few  weeks,  and  ripen  their  seeds,  in  which 
state  the  species  securely  passes  the  arid  season. 

376.  These  considerations  elucidate  the  process  of  forcing  plants, 
and  other  operations  of  horticulture,  by  which  we  are  enabled  to 
obtain  in  winter  the  flowers  and  fruits  of  summer.  The  gardener 
accomplishes  these  results  principally  by  skilful  alterations  of  the 
natural  period  of  repose.  He  gives  the  plant  an  artificial  period 
of  rest  by  dryness  at  the  season  when  he  cannot  command  cold, 
and  then,  by  the  influence  of  heat,  light,  and  moisture,  which  he  can 
always  command,  causes  it  to  grow  at  a  season  when  it  would  have 
been  quiescent.  Thus  he  retards  or  advances,  at  will,  the  periods 
of  flowering  and  of  rest,  or  in  time  completely  inverts  them. 


CHAPTER    VIII. 

OP   THE   INFLORESCENCE. 

377.  Inflorescence  is  the  term  used  to  designate  the  arrangement 
of  flowers  upon  the  stem  or  branch.  The  flower,  like  the  branch, 
is  evolved  from  a  bud.  Flower-buds  and  leaf-buds  are  often  so 
similar  in  appearance,  that  it  is  difficult  to  distinguish  one  from  the 
other  before  their  expansion.  The  most  conspicuous  parts  of  the 
flower  are  so  obviously  analogous  to  the  leaves  of  a  branch,  that 
they  are  called  in  common  language  the  leaves  of  the  flower.  Such 
a  flower  as  the  double  Camellia  appears  as  if  composed  of  a  rosette 
of  white  or  colored  leaves,  resembling,  except  in  their  color  and 
texture,  the  clusters  of  leaves  which  are  crowded  on  the  offsets  of 
such  plants  as  the  Houseleek  (Fig.  207).  We  therefore  naturally 
regard  a  flower-bud  as  analogous  to  a  leaf-bud ;  and  a  flower,  con- 
sequently, as  analogous  to  a  short  leafy  branch. 

378.  This  analogy  is  confirmed  by  the  position  which  flowers  oc- 
cupy. They  appear  at  the  same  situations  as  ordinary  buds,  and  at 
no  other  ;  that  is,  they  occupy  the  extremity  of  the  stem  or  branch, 
and  the  axil  of  the  leaves  (159,  1G5).     Consequently,  the  arrange- 

18* 


210 


THE    INFLORESCENCE. 


ment  of  the  leaves  governs  the  whole  arrangement  of  the  blossoms, 
as  well  as  that  of  the  branches.  The  almost  endless  variety  of 
modes  in  which  flowers  are  clustered  upon  the  stem,  many  of  them 
exhibiting  the  most  graceful  of  natural  forms,  all  implicitly  follow  the 
general  law  which  has  controlled  the  whole  development  of  the  vege- 
table from  the  beginning.  "We  have,  throughout,  merely  buds  termi- 
nating the  stem  and  branches,  and  buds  from  the  axil  of  the  leaves. 

379.  The  simplest  kind  of  inflorescence  is,  of  course,  that  of  a 

solitary  flower,  —  a  sin- 
gle flower-stalk  bearing 
a  single  flower ;  as  in 
Fig.  306  and  Fig.  327. 
The  flower  is  solitary  in 
both  these  instances  ;  but 

3°6  in  the  latter  case  it  oc- 

cupies the  summit  of  the  stem,  that  is,  it  stands  in  the  place  of 
a  terminal  bud  ;  in  the  former  it  arises  from  the  axil  of  a  leaf,  or 
represents  an  axillary  bud.  These  two  cases  exhibit,  in  their  great- 
est simplicity,  the  two  plans  of  inflorescence,  to  one  or  the  other  of 
which  all  flower-clusters  belong. 

380.  We  begin  with  the  second  of  these  plans  ;  in  which  the 
flowers  all  spring  from  axillary  buds  ;  while  the  terminal  bud,  de- 
veloping as  an  ordinary  branch,  continues  the  stem  or  axis  indefi- 
nitely. For  the  stem  in  such  case  may  continue  to  elongate,  and 
produce  a  flower  in  the  axil  of  every  leaf,  until  its  powers  are  ex- 
hausted (Fig.  307).     This  gives  rise,  therefore,  to  what  is  called 

381.  Indefinite  or  Indeterminate  Inflorescence.    The  primary  axis  is 

here  never  terminated  by  a  flower ;  but  the  secondary  axes  (from 
axillary  buds)  are  thus  terminated.  The  various  forms  of  indefi- 
nite inflorescence  which  in  descriptive  botany  are  distinguished  by 
special  names,  as  might  be  expected,  run  into  one  another  through 
intermediate  gradations.  In  nature  they  are  not  so  absolutely  fixed 
as  in  our  written  definitions  ;  and  whether  this  or  that  name  should 
be  used  in  a  particular  case  is  often  a  matter  of  fancy.  The  sub- 
joined account  of  the  principal  kinds  will  at  the  same  time  bring  to 
view  the  connection  between  them. 

382.  The  principal  kinds  of  indefinite  inflorescence  which  have 
received  distinctive  names  are  the  Raceme,  the  Corymb,  the  Umbel, 
the  Spike,  the  Head,  the  Spadix,  the  Catkin,  and  the  Panicle. 

[FIG.  306.     A  flowering  branch  of  Moneywort,  Lyshnachia  nummularia. 


INDETERMINATE  INFLORESCENCE. 


211 


383.  Before  illustrating  these,  one  or  two  terms,  of  common  oc- 
currence, may  be  denned.  A  flower  which  has  no  stalk  to  support 
it,  but  which  sits  directly  on  the  stem  or  axis  it  proceeds  from,  is 
said  to  be  sessile.  If  raised  on  a  stalk,  this  is  called  its  Peduncle. 
If  the  whole  flower-cluster  is  raised  on  a  stalk,  this 

keeps  the  name  of  peduncle,  or  common  peduncle  (Fig. 
307,  jo)  ;  and  the  stalk  of  each  particular  flower,  if  it 
have  any,  takes  the  name  of  Pedicel  or  partial 
peduncle  (p1).  The  portion  of  the  general  stalk  along 
which  flowers  are  disposed  is  called  the  axis  of  in- 
florescence, or,  when  covered  with  sessile  flowers,  the 
rhachis  (backbone),  and  sometimes  (as  when  thick 
and  covered  with  crowded  flowers)  the  receptacle. 
The  leaves  of  a  flower-cluster  generally  are  termed 
Bracts.  But  when  we  wish  particularly  to  distin- 
guish their  sorts,  those  on  the  peduncle,  or  main  axis, 
and  which  have  a  flower  in  their  axil,  take  the  name 
of  Bracts  (Fig.  307,  b)  ;  and  those  on  the  pedicels  or 
partial  flower-stalks,  if  any,  that  of  Bractlets  or 
Bracteoles  (&').  The  bracts  are  often  reduced  to 
a  minute  size,  so  as  to  escape  ordinary  notice :  they 
very  frequently  fall  off  when  the  flower-bud  in  their 
axil  expands,  or  even  earlier ;  and  sometimes,  as  in 
the  greater  part  of  the  Mustard  family,  they  altogether 
fail  to  appear. 

384.  A  Raceme  (Fig.  307,  308,  315)  is  that  form  of  flower-cluster 
in  which  the  flowers,  each  on  their  own  footstalk  or  pedicel,  are 
arranged  along  a  common  stalk  or  axis  of  infloresence ;  as  in  the 
Lily  of  the  Valley,  Currant,  Choke-Cherry,  Barberry,  &c.  The 
lowest  blossoms  of  a  raceme  are  of  course  the  oldest,  and  therefore 
open  first,  and  the  order  of  blossoming  is  ascending,  from  the  bot- 
tom to  the  top.  The  summit,  never  being  stopped  by  a  terminal 
flower,  may  go  on  to  grow,  and  often  does  so  (as  in  the  Snowberry, 
Shepherd's  Purse,  &c),  producing  lateral  flowers  one  after  another 
throughout  the  season.  In  the  raceme,  the  axis  of  inflorescence  is 
more  or  less  elongated,  and  the  pedicels  are  about  equal  in  length. 

385.  A  Corymb  (Fig.  309,  319)  is  the  same  as  a  raceme,  except 
that  the  lower  pedicels  are  elongated,  so  as  to  form  a  level-topped  or 
slightly  convex  bunch  of  flowers  ;  as  in  the  Hawthorn,  &c. 

FIG.  307.    A  Raceme,  -with  a  general  peduncle  (p),  pedicels  (p'),  bracts  (b),  and  bractlets  (V). 


¥ 


212 


THE   INFLORESCENCE. 


386.  All  Umbel  (Fig.  310)  differs  from  a  corymb  only  in  having 
all  the  pedicels  arising  from  the  same  apparent  point,  so  as  to  resem- 
ble the  rays  of  an  umbrella;  —  the  general  peduncle,  in  this  case, 
bearing  several  flowers  without  any  perceptible  elongation  of  the 


axis   of  infloresence.      The    Primrose   and   the   Milkweed   afford 

familiar  examples  of  the  simple  umbel. 

387.  A  corymb  being  evidently  the  same  as  a  raceme  with  a 
short  main  axis,  and  an  umbel  the  same 
as  a  corymb  with  a  still  shorter  axis, 
it  is  evident  that  the  outer  flowers  of 
an  umbel  or  corymb  correspond  to  the 
lowermost  in  the  raceme,  and  that  these 
will  first  expand,  the  blossoming  pro- 
ceeding regularly  from  the  base  to  the 
apex,  or  (which  is  the  same  thing)  from 
the  circumference  to  the  centre.  This 
mode  of  development  uniformly  takes 
place  when  the  flowers  arise  from  axil- 
lary buds  ;  on  which  account  the  indefi- 
nite mode  of  inflorescence  is  also  called 
the  centripetal. 

388.  In  all  the  foregoing  cases,  the 
flowers  are  raised  on  stalks,  or  pedicels. 
When  these  are  wanting,  or  so  short  as 
not  to  be  apparent,  a  Spike  or  Head  is 
produced. 
389.  A  Spike  is  the  same  as  the  raceme,  except  that  the  flowers 

are  sessile  ;  as  in  the  Plantain  (Fig.  311)  and  Mullein.     It  is  an  in- 

FIG.  308.     A  raceme.    309.  A  corymb.    310.  An  umbel. 

FIG.  311.    Young  spike  of  Plantago  major.    312.  Catkin  of  White  Birch. 


INDETERMINATE   INFLORESCENCE. 


213 


determinate  infloresence,  with  the  primary  axis  elongated,  and  the 
flowers  destitute  of  pedicels  or  with  only  very  short  ones.  Two 
varieties  of  the  spike  have  received  independent  names,  viz.  the 
Spadix  and  the  Ament. 

390.  A  Spadix  is  a  fleshy  spike  enveloped  by  a  large  bract  or  mod- 
ified leaf,  called  a  Spathe,  as  in  Calla  palustris  (Fig.  313),  the 
Indian  Turnip  (Fig.  314),  and  the  Skunk  Cabbage  (Fig.  1205). 


391.  An  Ament,  or  Catkin,  is  merely  that  kind  of  spike  with  scaly 
bracts  borne  by  the  Birch  (Fig.  312),  Poplar,  Willow,  and,  as  to  one 
of  the  two  sorts  of  flowers,  by  the  Oak,  Walnut,  and  Hickory,  which 
are  accordingly  called  amentaceous  trees.  Catkins  usually  fall  off 
in  one  piece,  after  flowering  or  fruiting,  especially  sterile  catkins. 

392.  The  Head,  or  Capitulum,  is  a  globular  cluster  of  sessile  flowers, 
like  that  of  Clover,  the  Button-Bush  (Fig.  320),  and  the  balls  of  the 
Buttonwood  or  Plane-tree.  It  is  a  many-flowered  centripetal  in- 
florescence, in  which  neither  the  primary  axis  nor  the  secondary 
axes  are  at  all  lengthened.  We  may  view  it  either  as  an  umbel 
without  any  pedicels,  or  as  a  spike  with  a  very  short  axis.  Gen- 
erally it  is  of  the  latter  character,  as  is  evident  in  a  Clover-head, 
where  what  was  first  a  head  frequently  elongates  into  a  spike  as  it 
grows  older. 

FIG.  313,  314.    Spadix  of  Calla  and  of  Arum,  with  the  spathe.    315.  A  raceme  of  Cherry. 
317.  A  cyme.    318.  Panicle  of  Meadow-Grass.    319.  A  corymb. 


214 


THE   INFLORESCENCE. 


393.  The  base  both  of  the  head  and  the  umbel  is  frequently  fur- 
nished with  a  number  of  imperfect  leaves  or  bracts,  crowded  into  a 


cluster  or  whorl,  termed  an  Involucre.     The  involucre  assumes  a 
great  variety  of  forms  ;  sometimes  resembling  a  calyx ;  and  some- 


FIG.  320.  Head  of  flowers  of  the  Button-bush,  Cephalanthus  occidentals. 
FIG.  321.  Plant  of  Cornus  Canadensis,  with  its  four-leaved  involucre  around  a  cluster  of  small 
flowers.    322.  A  separate  flower  enlarged. 
FIG.  323.    Flowering  branch  of  Cichory,  with  two  heads  of  ligulate  flowers. 


INDETERMINATE  INFLORESCENCE. 


215 


times  (as  in  Cornus  Florida,  or  the  common  Dogwood,  and  C.  Cana- 
densis, Fig.  321)  becoming  petal-like,  and  much  more  showy  than 
the  blossom  itself.  Here  it  is  at  once  distinguished  from  the  calyx 
or  corolla  by  its  including  a  number  of  flowers.  Sometimes,  how- 
ever, as  in  the  Mallow  and  Hibiscus,  the  involucre  forms  a  kind 
of  outer  calyx  to  each  flower. 

394.  The  axis,  or  rhachis  (382),  of  a  head  is  called  its  Recep- 
tacle. Frequently,  instead  of  being  globular  or  oblong,  it  is  flat  or 
depressed,  and  dilated  horizontally,  so  as  to  allow  a  large  number  of 
flowers  to  stand  on  its  level  or  merely  convex  surface ;  as  in  the  Sun- 
flower, Aster,  Marigold,  Dandelion,  and  Cichory  (Fig.  323).  Here, 
as  in  Fig.  321,  a  set  of  bracts  form  an  involucre,  surrounding  the 
dense  head  of  flowers.  And  as  the  involucre  considerably  resembles 
a  calyx,  Avhile  the  outer  flowers,  often  of  a  peculiar  sort,  are  readily 
mistaken  for  petals,  the  head  in  these  and  similar  plants  was  called 
a  compound  jftower  by  the 
older  botanists.  Fig.  324  rep- 
resents a  section  through  a 
head  of  such  flowers  in  a  Co- 
reopsis ;  and  Fig.  325  is  a  slice 
of  the  same,  more  enlarged, 
displaying  some  of  the  sepa- 
rate flowers.     In  Coreopsis, 

as  in  the  Sunflower,  Yarrow,  324 

&c.,  each  blossom  of  the  head  is  subtended  by  its  bract  (b)  ;  and 
the  bracts  in  such  cases  are  called  Palece  or  Chaff. 


395.  The   Fig   presents  a  case  of  very  singular  inflorescence 

FIG.  324.     Vertical  section  of  a  head  of  flowers  of  a  Coreopsis. 

FIG.  325.  A  slice  of  Fig.  324,  more  enlarged,  with  one  tubular  perfect  flower  (a)  left  stand- 
ing on  the  receptacle,  and  subtended  by  its  bract  or  chaff  (b);  also  one  ligulate  and  neutral  ray- 
flower  (c),  and  part  of  another:  d,  section  of  bracts  or  leaves  of  the  involucre. 


216 


THE    INFLORESCENCE. 


(Fig.  590-592),  where  the  flowers  apparently  occupy  the  inside 
instead  of  the  outside  of  the  axis,  being  enclosed  within  the  fleshy 
receptacle,  which  is  hollow  and  nearly  closed  at  the  top.  So  that 
while  a  Sunflower,  or  the  like,  is  an  inflorescence  imitating  a  blos- 
som, a  fig  is  an  inflorescence  imitating  a  fruit.  Indeed,  it  is  much 
like  a  mulberry  (Fig.  593)  or  a  pine-apple,  turned  inside  out. 

396.  The  foregoing  are  all  forms  of  simple  inflorescence ;  the 
ramification  not  passing  beyond  the  first  step ;  the  lateral  buds  being 
at  once  terminated  by  a  single  flower.  But  the  lateral  flower- 
stalks  may  themselves  branch,  just  as  ordinary  branches  give  rise 
to  branchlets :  then  the  inflorescence  becomes  compound.  If  the 
branches  of  a  raceme  are  prolonged,  and  bear  other  flowers  on  pedi- 
cels similarly  arranged,  a  compound  raceme  is  produced ;  or  if  the 
flowers  are  sessile,  a  compound  sjrike  is  formed.  A  corymb,  the 
branches  of  which  are  similarly  divided,  forms  a  compound  corymb  ; 
and  an  umbel,  where  the  branches  (often  called  rays)  bear  smaller 
umbels  at  their  apex,  is  termed  a  compound  um- 
bel ;  as  in  the  Caraway,  Parsnip,  and  almost  all 
the  species  of  the  family  UmbeUiferse,  which  is 
so  named  on  this  account. 

397.  For  these  secondary  umbels,  a  good  Eng- 
lish name  has  been  employed  by  Dr.  Darlington, 
that  of  Umbellets.  Their  involucre,  when 
they  have  any,  is  distinguished  from  that  of  the 
principal  umbel  by  the  name  of  Invoeucel. 

398.  When  the  inflorescence  is  compound,  it  is 
readily  seen  that  the  different  kinds  of  inflores- 
cence may  be  combined ;  the  first  ramification 
following  one  plan,  and  the  subdivision  another. 
The  combination  is  usually  expressed  by  a  de- 
scriptive phrase,  as  "  spikes  racemose,  or  ra- 
cemed,"  "  heads  corymbose,"  &c.  The  combina- 
tion of  the  raceme  and  the  corymb  or  the  cyme 
gives  rise  to  a  form  of  inflorescence  which  has  a 
technical  name,  viz. :  — 

399.  The  Panicle.  This  is  formed  when  the 
secondary  axes  of  a  raceme  branch  in  a  corymbose  manner,  as  in 
most  Grasses  (Fig.  318,  32 G),  or  when  those  of  a  corymb  divide  in  the 
manner  of  a  raceme.     And  the  name  is  applied  to  almost  any  open 

FIG.  326.    A  panicle.    (Compare  with  Fig.  307.) 


DETERMINATE    INFLORESCENCE. 


217 


and  more  or  less  elongated  inflorescence  which  is  irregularly  branched 
twice,  thrice,  or  a  greater  number  of  times. 

400.  A  Th)TSUS,  or  Thyi'SC,  is  a  compact  panicle  of  a  pyramidal,  oval, 
or  oblong  outline  ;  such  as  the  cluster  of  flowers  of  the  Lilac  and 
Horsechestnut,  a  bunch  of  grapes,  &c. 

401.  Definite  or  Determinate  Inflorescence.    In  this  class,  the  flowers 

all  represent  terminal  buds  (380).  The  primary  axis  is  directly 
terminated  by  a  single  flower-bud,  as  in  Fig.  327,  and  its  growth 
is  of  course  arrested.  Here  we  have  a  solitary  terminal  flower. 
Further  growth  can  take  place  only  by  the  development  of  secondary 
axes  from  axillary  buds.  These  may  develop  at  once  as  peduncles, 
or  as  leafy  branches  ;  but  they  are  in  either  case  arrested,  sooner  or 
later,  by  a  flower-bud,  just  as  the  primary  axis  was  (Fig.  328).  If 
further  development  ensues,  it  is  by  the  production  of  branches  of  the 
third  order,  from  the  axils  of  leaves  or  bracts  on  the  branches  of  the 
second  order  (Fig.  329)  ;  and  so  on.  Hence  this  mode  of  inflo- 
rescence is  said  to  be  definite  or  determinate,  in  contradistinction  to 
the  indeterminate  mode,  already  treated  of,  where  the  primary  or 
leading  axes  elongate  indefinitely,  or  merely  cease  to  grow  from  the 
failure  of  nourishment,  or  some  other  extrinsic  cause.  The  most 
common  and  most  regular  cases  of  determinate  inflorescence  occur  in 
opposite-leaved  plants,  for  obvious  reasons  ;  and  such  are  accordingly 
chosen  for  the  subjoined  illustrations.  But  the  Rose,  Potentilla,  and 
Buttercup  furnish  familiar  examples  of  the  kind  in  alternate-leaved 
plants. 


402.  The  determinate  mode  of  inflorescence  assumes  forms  which 
may  closely  imitate  those  of  the  indeterminate  kind,  already  de- 
scribed, and  Avith  which  they  have  been  confounded.  When,  for  ex- 
ample, all  the  secondary  axes  connected  with  the  inflorescence  are 
arrested  by  terminal  flowers,  without  any  onward  growth  except 

FIG.  327  -  329.    Diagrams  of  regular  forms  of  determinate  or  centrifugal  inflorefffnce. 

19 


218  THE   INFLORESCENCE. 

what  forms  their  footstalks  or  pedicels,  and  these  are  nearly  equal  in 
length,  a  raeerae-like  inflorescence  is  produced,  as  in  Fig.  330  ;  or 
when  the  flowers  have  scarcely  any  pedicels,  the  spike  is  imitated. 
These  are  distinguished  from  the  true  raceme  and 
spike,  however,  by  the  reverse  order  of  development 
of  the  blossoms ;  the  terminal  one  opening  earliest,  and 
the  others  expanding  in  succession  from  above  down- 
wards ;  while  the  blossoming  of  the  raceme  proceeds 
from  below  upwards.  Or  when,  by  the  elongation  of 
the  lower  secondary  axes,  a  corymb  is  imitated,  the 
flowers  are  found  to  expand  in  succession  from  the 
centre  of  each  ramification,  beginning  in  the  centre  of 
the  cluster,  while  the  contrary  occurs  in  the  corymb. 
That  is,  Avhile  the  order  in  indeterminate  inflorescence 
is  centripetal  (387),  that  of  the  determinate  mode  is 
centrifugal.  When  the  determinate  inflorescence  as- 
sumes the  flattish  or  convex  form,  which  it  more  com- 
monly does,  it  has  a  distinctive  name,  viz. :  — 

403.  The  Cyme.  This  is  a  flat-topped,  rounded  or  expanded  in- 
florescence, whether  simple  or  compound,  of  the  determinate  class  ; 
of  which  those  of  the  Laurustinus,  Elder,  Dogwood,  and  Hydrangea 
(Fig.  420)  are  fully  developed  and  characteristic  examples.  In  com- 
pound and  compact  cymes,  such  as  those  of  the  Laurustinus,  Dogwood, 
&c,  the  leaves  or  bracts  are  usually  minute,  rudimentary,  or  abor- 
tive, and  all  the  numerous  flower-buds  of  the  cluster  are  fully  formed 
before  any  of  them  expand  ;  and  the  blossoming  then  runs  through 
the  whole  cluster  in  a  short  time,  commencing  in  the  centre  of  the 
cyme,  and  then  in  the  centre  of  each  of  its  branches,  and  thence  pro- 
ceeding centrifugally.  But  in  the  Chickweeds  (Fig.  331),  in  Hy- 
pericum, and  many  similar  plants,  the  successive  production  of  the 
branches  and  the  evolution  of  the  flowers,  beginning  with  that  Avhich 
arrests  the  growth  of  the  primary  axis,  go  on  gradually  through  the 
Avhole  summer,  until  the  powers  of  the  plant  are  exhausted,  or  until 
all  the  branchlets  or  peduncles  are  reduced  to  single  internodes,  or 
pedicels  destitute  of  leaves,  bracts,  or  bractlets,  when  no  further  de- 
velopment can  take  place.  Such  cases  enable  us  to  study  the  deter- 
minate inflorescence  to  advantage,  and  to  follow  the  successive  steps 
of  the  ramification  by  direct  observation. 

404.  A  Cymule  ( Cfymula)  is  a  diminutive  cyme,  or  a  branch  or 
cluster  of  a  compound  cyme. 

FIG.  330.    Definite  inflorescence  imitating  a  raceme. 


DETERMINATE  INFLORESCENCE. 


219 


405.  The  Fascicle  is  a  very  compact  cyme,  with  upright  or  ap- 
pressed  branches  ;  as  in  the  Sweet  "William. 

406.  A  Glomcmle  is  a  cyme  condensed  into  a  kind  of  head.     It  is 
to  the  cyme  what  the  head  is  to  the  corymb  or  umbel. 


407.  There  are  several  abnormal  modifications  of  definite  inflo- 
rescence, arising  from  irregular  development,  or  the  suppression  of 
parts,  such  as  the  non-appearance  sometimes  of  the  central  flower, 
or  often  of  one  of  the  lateral  branches  at  each  division ;  as  in  the 
ultimate  ramifications  of  Fig.  331,  where  one  of  the  lateral  pedicels 
is  wanting.  When  this  deviation  is  completely  manifested,  that  is, 
when  one  of  the  side  branches  regularly  fails,  the  cyme  is  apparently 
converted  into  a  kind  of  one-sided  raceme,  and  the  flowers  seem  to 
expand  from  below  upwards,  or  centripetally.  The  diagram,  Fig. 
332,  when  compared  with  Fig.  331,  explains  this  anomaly.  The 
place  of  the  axillary  branch  which  fails  to  develop  at  each  ramifica- 
tion is  indicated  by  the  dotted 
lines.  Cases  like  this  occur 
in  several  Hypericums,  and 
in  some  other  opposite-leaved 
plants.  An  analogous  case  oc- 
curs in  many  alternate-leaved 
plants  ;  where  the  stem,  being 
terminated  by  a  flower,  is  con- 
tinued by  a  branch  from  the 
axil  of  the  uppermost  leaf  or 
bract ;   this,  bearing  a  flower,  332  333 

is  similarly  prolonged  by  a  secondary  branch ;  that  by  a  third,  and 
so  on  ;  as  is  shown  in  the  diagram,  Fig.  333.      Such  forms  of  inflo- 


FIG.  331.    The  open,  progressively  developed  cyme  of  Alsine  Michauxii. 
FIG.  332,  333.    Plan  of  two  modifications  of  helicoid  cymes  or  false  racemes. 


220  THE   INFLORESCENCE. 

rescence,  which  Ave  may  observe  in  Drosera,  Sedum,  and  Hounds- 
tongue,  imitate  the  raceme  so  nearly,  that  they  have  commonly  been 
considered  as  of  that  kind.  They  are  distinguishable,  however,  by 
the  position  of  the  flowers  opposite  the  leaf  or  bract,  or  at  least  out 
of  its  axil ;  while  in  the  raceme,  and  in  every  modification  of  cen- 
tripetal inflorescence,  the  flowers  necessarily  spring  from  the  axils. 
But  if  the  bracts  disappear,  as  they  commonly  do  in  the  Forget-me- 
not,  &c,  the  true  nature  of  the  inflorescence  is  not  readily  made  out. 
The  undeveloped  summit  is  usually  circinate,  or  coiled  in  a  spiral 
manner  (Fig.  219),  gradually  unrolling  as  the  flowers  grow  and 
expand,  and  becoming  straight  in  fruit  On  account  of  this  coiled 
arrangement,  such  cymes  or  false  racemes  are  said  to  be  helicoid, 
or  scorpioid. 

408.  The  cyme,  raceme,  head,  &c,  as  well  as  the  one-flowered 
peduncle,  may  arise,  either  at  the  extremity  of  the  stem  or  leafy 
branch  (terminal),  or  in  the  axil  of  the  leaves  {axillary).  The  case 
of  a  peduncle  opposite  a  leaf,  as  in  the  Poke,  the  Grape-vine,  &c,  is 
just  that  illustrated  in  Fig.  333,  except  that  in  these  cases  the  peduncles 
bear  a  cluster  of  flowers  instead  of  a  single  one.  The  tendrils  of 
the  Vine  (Fig.  1G1)  occupy  the  same  position,  and  are  of  the  same 
nature.  In  a  growing  Grape-vine,  it  is  evident  that  the  uppermost 
tendril  really  terminates  the  stem ;  and  that  the  latter  is  continued 
by  the  growth  of  the  axillary  bud,  situated  between  the  petiole  and 
the  peduncle ;  the  branch  thus  formed,  assuming  the  direction  of  the 
main  stem,  and  appearing  to  be  its  prolongation,  throws  the  peduncle 
or  tendril  to  the  side  opposite  the  leaf. 

409.  The  extra-axillary  peduncles  of  most  species  of  Solanum,  &c. 
are  terminal  peduncles,  which  have  become  lateral  by  the  evolution 
of  an  axillary  branch,  with  which  the  peduncle  or  the  petiole  is 
united  for  some  distance.  Such  peduncles  sometimes  come  from 
extra-axillary  accessory  buds  (169). 

410.  In  the  Linden  (Fig.  742)  the  peduncle  appears  to  spring 
from  the  middle  of  a  peculiar  foliaceous  bract.  But  this  is  rather 
a  bractlet,  inserted  on  the  middle  of  the  peduncle,  and  decurrent 
down  to  its  base. 

411.  A  peduncle  which  arises  from  the  stem  at  or  beneath  the 
surface  of  the  ground,  as  in  Bloodroot,  the  Primrose,  the  so-called 
stemless  Violets,  &c,  is  called  a  radical  peduncle,  or  a  Scape. 

412.  A  combination  of  the  two  classes  of  inflorescence  is  not  un- 
usual, the  general  axis  developing  in  one  way,  but  the  separate 


THE   FLOWER.  221' 

flower-clusters  in  the  other.  Thus  the  heads  of  the  Sunflower  and 
of  all  the  so-called  compound  flowers  (394)  are  centripetal,  the 
flowers  expanding  regularly  from  the  margin  or  circumference  to  the 
centre  ;  while  the  branches  that  bear  the  heads  ai-e  developed  in  the 
centrifugal  mode,  the  central  heads  being  earliest  to  come  into  blos- 
som. This  is  exactly  reversed  in  all  Labiatre  (plants  of  the  Mint 
tribe) ;  where  the  stem  grows  on  indefinitely,  producing  axillary 
clusters  in  the  form  of  a  general  raceme  or  spike,  which  blossoms 
from  below  upwards ;  while  the  flowers  of  each  cluster  form  a  cyme, 
and  expand  in  the  centrifugal  manner.  These  cymes,  or  cymules 
(404),  are  usually  close  and  compact,  and  being  situated  one  in  each 
axil  of  the  opposite  leaves,  the  two  together  frequently  form  a  clus- 
ter which  surrounds  the  stem,  like  a  whorl  or  verticil  (as  in  the 
Catnip  and  Horehound)  :  hence  such  flowers  are  often  said  to  be 
whorled  or  I'erticillate,  which  is  not  really  the  case,  as  they  evidently 
all  spring  from  the  axils  of  the  two  leaves.  Tho  apparent  verticil 
of  this  kind  is  sometimes  termed  a  Verticillaster. 

413.  True  whorled  flowers  occur  only  in  some  plants  with  whorled 
leaves,  as  in  Hippuris  and  the  Water  Milfoil. 


CHAPTER    IX. 

OP   THE   FLOWER. 

Sect.  I.    Its  Organs,  or  Component  Parts. 

414.  Having  glanced  at  the  circumstances  which  attend  and  con- 
trol the  production  of  flowers,  and  considered  the  laws  which  govern 
their  arrangement,  we  have  next  to  inquire  what  the  flower  is  com- 
posed of. 

415.  The  Flower  (117)  assumes  an  endless  variety  of  forms  in 
different  species,  so  that  it  is  very  difficult  properly  to  define  it. 
The  name  was  earliest  applied,  as  it  is  still  in  popular  language 
generally  applied,  to  the  delicate  and  gayly  colored  leaves  or  petals, 
so  different  from  the  sober  green  of  the  foliage.  But  the  petals, 
and  all  these  bright  hues,  are  entirely  wanting  in  many  flowers, 
while  ordinary  leaves  sometimes  assume  the  brilliant  coloring  of  the 

19* 


222 


THE    FLOWKU. 


blossom      The  stamens  and  pistils  are  the  characteristic  organs  of 
the  flower  ;  hut  sometimes  one  or  the  other  of  these  disappear  from 
334  a  particular  flower,  and  both  are  absent  from 

full  double  Roses,  Camellias,  &c,  in  which  we 
have  only  a  regular  rosette  of  delicate  leaves. 
This,  however,  is  an  unnatural  state,  the  conse- 
quence of  protracted  cultivation. 

416.  The  flower  consists  of  the  organs  of  re- 
production of  a  Phamogamous  plant  (114),  and 
their  envelopes.  A  complete  flower  consists  of 
the  essential  organs  of  reproduction  (viz.  stamens 
and  pistils),  surrounded  by  two  sets  of  leaves 
or  envelopes  which  protect  them.  The  latter 
are  of  course  exterior  or  lower  than  the  former, 
which  in  the  bud  they  enclose. 

417.  The  Floral  Envelopes,  then,  are  of  two 

sorts,  and  occupy  two  circles,  one  above  or 
Those  of  the  lower  circle,  the  exterior  envelope 
in  the  flower-bud,  form  the  Calyx  :  they  commonly  exhibit  the 
green  color  and  have  much  the  appear- 
ance of  ordinary  leaves.  Those  of  the 
inner  circle,  which  are  commonly  of  a 
more  delicate  texture  and  brighter  color, 
and  form  the  most  showy  part  of  the  . 
blossom,  compose  the  Corolla.  The  /\  11  v\)  \\  \  || 
several  parts  or  leaves  of  the  corolla  are  W  Wilt 
called  Petals  :  and  the  leaves  of  the  3iS 
calyx  take  the  corresponding  name  of  Sepals.  One  of  the  five 
sepals  of  the  flower  represented  in  Fig.  334  is  separately  shown  in 
Fig.  336  ;  and  one  of  the  petals  in  Fig.  337.  The  calyx  and  corolla, 
taken  together,  or  the  whole  floral  envelopes,  whatever  they  may  con- 
sist of,  are  sometimes  called  the  Perianth  (Periantkium  or  Peri- 
goniuni). 

418.  The  Essential  Organs  of  the  flower  are  likewise  of  two  kinds, 
and  occupy  two  circles  or  rows,  one  within  the  other.     The  first  of 


within  the  other. 


FIG.  334.  The  complete  flower  of  a  Crassula.  335.  Diagram  of  its  cross-section  in  the  bud, 
showing  the  relative  position  of  its  parts.  The  five  pieces  of  the  exterior  circle  are  sections  of 
the  sepals  ;  the  next,  of  the  petals  ;  the  third,  of  the  stamens  through  their  anthers  ;  the  in- 
nermost, of  the  five  pistils. 

FIG.  336.  A  sepal ;  337,  a  petal ;  338,  a  stamen  ;  and  339,  a  pistil  from  the  flower  repre- 
sented in  Fig.  334. 


ITS    ORGANS    OR    TARTS. 


223 


these,  those  next  within  the  petals,  are  the  Stamens  (Fig.  338). 
A  stamen  consists  of  a  column  or  stalk,  called  the  Filament  (Fig. 
340,  a),  and  of  a  rounded  hody,  or  case,  termed  the  An- 
ther (b),  filled  with  a  powdery  suhstance  called  Pol- 
len, which  it  discharges  through  one  or  more  slits  or 
openings.  The  older  botanists  had  no  general  term  for 
the  stamens  taken  collectively,  analogous  to  that  of  corolla 
for  the  entire  whorl  of  petals,  and  of  calyx  for  the  whorl 
of  sepals.  A  name  has,  however,  recently  been  pro- 
posed for  the  staminate  system  of  a  flower,  which  it  is 
occasionally  convenient  to  use  ;  that  of  Andrcecium. 

419.  The  remaining,  or  seed-bearing  organs,  which  occupy  the 
centre  or  summit  of  the  flower,  to  whose  protection  and  perfection 
all  the  other  parts  of  the  flower  are  in  some  way  subservient,  are 
termed  the  Pistils.  To  them  collectively  the  name  of  Gyn^ecilm 
has  been  applied.  One  of  them  is  separately  shown  in  Fig.  339. 
This  is  seen  more  magnified  and  cut  across  in  Fig.  342  ;  and  a  dif- 
ferent one,  longitudinally  divided, 
so  as  to  exhibit  the  whole  length 
of  its  cavity,  or  cell,  is  represent- 
ed in  Fig.  341. 

420.  A  pistil  is  distinguished 
into  three  parts ;  namely,  the 
Ovary  (Fig.  341,  «),  the  hollow 
portion  at  the  base  which  con- 
tains the  Ovules,  or  bodies  des- 
tined to  become  seeds  ;  the  Style 
(b),  or  columnar  prolongation  of  the  apex  of  the 
ovary;  and  the  Stigma  (c),  a  portion  of  the  sur- 
face of  the  style  denuded  of  epidermis,  sometimes 
a  mere  point  or  a  small  knob  at  the  apex  of  the 
style,  but  often  forming  a  single  or  double  line 
running  down  a  part  of  its  inner  face,  and  assum- 
ing a  great  diversity  of  appearance  in  different 
plants. 

FIG.  340.    A  stamen,  with  the  anther  (b)  discharging  its  pollen :  a,  the  filament. 

FIG.  341.  Vertical  section  of  a  pistil,  showing  the  interior  of  its  ovary,  a,  to  one  side  of 
which  are  attached  numerous  ovules,  d  :  above  is  the  style,  b,  tipped  by  the  stigma,  c. 

FIG.  342.  A  Pistil  of  Crassula,  like  that  of  Fig.  339,  but  more  magnified,  and  cut  across 
through  the  ovary,  to  show  its  cell,  and  the  ovules  it  contains.  At  the  summit  of  the  style  is 
Been  a  somewhat  papillose  portion,  destitute  of  epidermis,  extending  a  little  way  down  the  in- 
ner face  :  this  is  the  stigma. 


224 


THE   FLOWER. 


421.  All  the  organs  of  the  flower  are  situated  on,  or  grow  out  of, 
the  apex  of  the  flower-stalk,  into  which  they  are  said,  in  botanical  lan- 
guage, to  be  inserted,  and  which  is  called  the  Torus,  or  Receptacle. 
This  is  the  axis  of  the  flower,  to  which  the  floral  organs  are  attached 
(just  as  leaves  are  to  the  stem)  ;  the  calyx  at  its  very  base ;  the 
petals  just  within  or  above  the  calyx  ;  the  stamens  just  within  the 
petals  ;  and  the  pistils  within  or  above  the  stamens  (Fig.  343). 

d      c  422.  Such  is  the  struct- 

ure of  a  complete  and  regu- 
lar flower  ;  which  we  take 
as  the  type,  or  standard  of 
comparison.  The  calyx 
and  corolla  are  termed  pro- 
tecting organs.  In  the  bud, 
they  envelope  the  other 
parts  :  the  calyx  sometimes 
forms  a  covering  even  for 
the  fruit ;  and  when  it  retains  its  leaf-like  texture  and  color,  it  as- 
similates the  sap  of  the  plant  with  the  evolution  of  oxygen  gas,  in 
the  same  manner  as  do  true  leaves  :  the  corolla  elaborates  honey  or 
other  secretions,  for  the  nourishment,  as  is  supposed,  of  the  stamens 
and  pistils.  Neither  the  calyx  nor  corolla  is  essential  to  a  flower, 
one  or  both  being  not  unfrequently  wanting.  The  stamens  and  pis- 
tils are,  however,  essential  organs,  since  both  are  necessary  to  the 
production  of  seed.  But  even  these  are  not  always  both  present  in 
the  very  same  flower ;  as  will  be  seen  when  we  come  to  notice  the 
diverse  forms  which  the  blossom  assumes,  and  to  compare  them  with 
our  pattern  flower. 


Sect.  II.     The  Theoretical  Structure  or  General  Mor- 
phology of  the  Flower. 


423.  To  obtain  at  the  outset  a  correct  idea  of  the  flower,  it  is 
needful  here  to  consider  the  relation  which  its  organs  sustain  to  the 
organs  of  vegetation.  Taking  the  blossom  as  a  whole,  we  have 
recognized,  in  the  chapter  on  Inflorescence  (377),  the  identity  of 
flower-buds  and  leaf-buds  as  to  situation,  &c.     Flowers,  consequently, 

FIG.  343.    Parts  of  the  flower  of  a  Stonecrop,  Sedum  ternatum,  two  of  each  sort,  and  the 
receptacle,  displayed  :  a,  sepal :  6,  petal :  c,  stamen  :  d,  pistil. 


ITS    THEORETICAL    STRUCTURE.  225 

are  at  least  analogous  to  branches,  and  the  leaves  of  the  flower  are 
analogous  to  ordinary  leaves. 

424  But  the  question  which  now  arises  is,  whether  the  leaves  of 
the  stem  and  the  leaves  and  the  more  peculiar  organs  of  the  flower 
are  not  homologous  parts,  that  is,  parts  of  the  same  fundamental 
nature,  although  developed  in  different  shapes  that  they  may  sub- 
serve different  offices  in  the  vegetable  economy  ; — just  as  the  arm 
of  man,  the  fore-leg  of  quadrupeds,  the  wing-like  fore-leg  of  the  bat, 
the  true  wing  of  birds,  and  even  the  pectoral  fin  of  fishes,  all  repre- 
sent one  and  the  same  organ,  although  developed  under  widely  dif- 
ferent forms  and  subservient  to  more  or  less  different  ends.  The 
plant  continues  for  a  considerable  time  to  produce  buds  which  de- 
velop into  branches.  At  length  it  produces  buds  which  expand  into 
blossoms.  Is  there  an  entirely  new  system  introduced  when  flowers 
appear  ?  Are  the  blossoms  formed  upon  such  a  different  plan,  that 
the  general  laws  of  vegetation,  which  have  sufficed  for  the  interpre- 
tation of  all  the  phenomena  up  to  the  inflorescence,  are  to  afford  no 
further  clew  ?  Or,  on  the  contrary,  now  that  peculiar  results  are  to 
be  attained,  are  the  simple  and  plastic  organs  of  vegetation  —  the 
stem  and  leaves  —  developed  in  new  and  peculiar  forms  for  the  ac- 
complishment of  these  new  ends  ?  The  latter,  doubtless,  is  the  coi'- 
rect  view.  The  plant  does  not  produce  essentially  new  kinds  of 
organs  to  fulfil  the  new  conditions,  but  adopts  and.  adapts  the  old. 
Notwithstanding  these  new  conditions  and  the  successively  increas- 
ing difference  in  appearance,  the  fundamental  laws  of  vegetation 
may  be  traced  from  the  leafy  branch  into  and  through  the  flower. 
That  is,  the  parts  of  the  blossom  are  homologous  with  leaves,  are 
leaves  in  other  forms  than  that  of  foliage. 

425.  The  student  will  have  observed,  that  in  vegetation  no  new 
organs  are  introduced  to  fulfil  any  particular  condition,  but  the  com- 
mon elements,  the  root,  stem,  and  leaves,  are  developed  in  peculiar 
and  fitting  forms  to  subserve  each  special  purpose.  Thus,  the  same 
organ  which  constitutes  the  stem  of  an  herb,  or  the  trunk  of  a  tree, 
we  recognize  in  the  trailing  vine,  or  the  twiner,  spirally  climbing 
other  stems,  in  the  straw  of  "Wheat  and  other  Grasses,  in  the  colum- 
nar trunk  of  the  Palm,  in  the  flattened  and  jointed  Opuntia,  or 
Prickly  Pear,  and  in  the  rounded,  lump-like  body  of  the  Melon- 
Cactus.  So,  also,  branches  harden  into  spines  in  the  Thorn,  or,  by 
an  opposite  change,  become  flexible  and  attenuated  tendrils  in  the 
Vine,  and  runners  in  the   Strawberry ;  or,  when  developed  under 


226  THE    FLOWER. 

ground,  they  assume  the  aspect  of  creeping  roots,  and  sometimes 
form  thickened  rootstalks,  as  in  the  Calamus  and  Solomon's  Seal,  or 
tubers,  as  in  the  Potato.  But  the  type  is  readily  seen  through 
these  disguises.  They  are  all  mere  modifications  of  the  stem.  The 
leaves,  as  we  have  already  seen,  appear  under  a  still  greater  variety 
of  forms,  some  of  them  as  "widely  different  from  the  common  type  of 
foliage  as  can  be  imagined  ;  such,  for  example,  as  the  thickened  and 
obese  leaves  of  the  Mesembryanthemums  ;  the  intense  scarlet  or 
crimson  floral  leaves  of  the  Euchroma,  or  Painted-Cup,  of  the 
Poinsettia  of  our  conservatories,  and  of  several  Mexican  Sages  ;  the 
tendrils  of  the  Pea  tribe  ;  the  pitchers  of  Sarracenia  (Fig-  300), 
and  also  those  of  Nepenthes  (Fig.  301),  which  are  leaf,  tendril,  and 
pitcher  combined.  The  leaves  also  appear  under  very  different 
aspects  in  the  same  individual  plant,  according  to  the  purposes  they 
are  intended  to  subserve.  The  first  pair  of  leaves,  or  cotyledons, 
when  gorged  with  nutritive  matter  for  the  supply  of  the  earliest 
wants  of  the  embryo  plant,  as  in  the  Almond,  Bean,  Pea,  &c.  (Fig. 
108-120),  would  seem  to  be  peculiar  organs.  But  in  some  of 
these  cases,  when  they  have  discharged  this  special  office  in  ger- 
mination, by  yielding  to  the  young  plant  the  store  of  nourishment 
with  which  they  are  laden,  they  imperfectly  assume  the  color  and 
appearance  of  foliage ;  while  in  other  cases,  as  in  the  Convolvulus 
(Fig.  123)  and  the  Maple  (Fig.  104),  they  are  green  and  foliaceous 
from  the  first.  As  the  stem  develops,  the  successive  leaves  vary  in 
form  or  size,  according  to  the  varying  vigor  of  vegetation.  In  our 
trees,  we  trace  the  last  leaves  of  the  season  into  bud-scales  ;  and  in 
the  returning  spring  we  may  often  trace  the  scales  of  opening  buds 
through  intermediate  states  back  again  into  true  leaves  (161). 

426.  The  analogies  of  vegetation  would  therefore  lead  us  to  ex- 
pect, that  in  flowering  the  leaves  would  be  wrought  into  new  forms, 
to  subserve  peculiar  purposes.  In  the  chapter  on  Inflorescence,  we 
have  already  learned  that  the  arrangement  and  situation  of  flowers 
upon  the  stem  conform  to  this  idea.  In  this  respect,  flowers  are 
absolutely  like  branches.  The  aspect  of  the  floral  envelopes  favors 
the  same  view.  We  plainly  discern  the  leaf  in  the  calyx,  and 
again,  more  delicate  and  refined,  in  the  petals.  In  numberless  in- 
stances, we  find  a  regular  transition  from  ordinary  leaves  into  sepals, 
and  from  sepals  into  petals.  And,  while  even  the  petals  are  occa- 
sionally green  and  herbaceous,  the  undoubted  foliage  sometimes 
assumes  a  delicate  texture  and  the  brightest  hues  (425).     The  per- 


ITS    THEORETICAL    STRUCTURE. 


227 


feet  gradation  of  leaves  or  bracts  into  sepals  is  extremely  common. 
The  transition  of  sepals  into  petals  is  exemplified  in  almost  every 
case  where  there  are  more  than  two  rows  of  floral  envelopes ;  as  in 
the  Magnolia,  and  especially  in  the  White  Water-Lily,  various  kinds 
of  Cactus,  the  Ulicium,  or  Star- Anise  of  the  Southern  States,  and 
the  Calycanthus,  or  Carolina  Allspice,  which  present  several  series 
of  floral  envelopes,  all  nearly  alike  in  color,  texture,  and  shape  ;  but 
how  many  of  the  innermost  are  to  be  called  petals,  and  how  the  re- 
mainder are  to  be  divided  between  sepals  and  bracts,  is  entirely  a 
matter  of  arbitrary  opinion.  In  fact,  the  only  real  difference  be- 
tween the  calyx  and  corolla  is,  that  the  former  is  the  outer,  and  the 
latter  an  inner  series  of  floral  envelopes.  Sometimes  the  gradation 
extends  one  step  farther,  and  exhibits  an  evident  transition  of  petals 
into  stamens  ;  showing  that  these  are  of  the  same  fundamental 
nature  as  the  floral  envelopes,  which  are  manifestly  traceable  back 
to  leaves.  The  White  Water-Lily  (Fig.  344)  exhibits  this  latter 
transition,  as  evi- 
dently as  it  does 
that  of  sepals  into 
petals.  Here  the 
petals  occupy  sev- 
eral whorls ;  and 
while  the  exterior 
are  nearly  undis- 
tinguishahle  from 
the  calyx,  the  in- 
ner are  reduced  in- 
to organs  which  are 
neither  well-formed 
petals  nor  stamens, 
but  intermediate  be- 
tween the  two.  They  are  merely  petals  of  a  smaller  size,  with 
their  summits  contracted  and  transformed  into  imperfect  anthers, 
containing  a  few  grains  of  pollen :  those  of  the  series  next  within 
are  more  reduced  in  size,  and  bear  perfect  anthers  at  the  apex ;  and 
a  still  further  reduction  of  the  lower  part  of  the  petal  completes  the 
transition  into  stamens  of  ordinary  appearance. 

427.  By  regular  gradations,  therefore,  the  leaf  may  be  traced  to 

FIG.  344.     A  sepal,  petals,  bodies  intermediate  between  petals  and  stamens,  and  true  sta- 
mens, of  the  White  Water-Lily. 


228 


THE    FLOWER. 


the  petal  and  the  stamen.  But  we  could  not  expect  to  meet  with 
intermediate  states  between  a  stamen  and  a  pistil,  except  as  a  mon- 
strosity. The  same  organ  could  not  fulfil  such  antagonistic  offices. 
Nevertheless,  stamens  changing  into  pistils  are  occasionally  found  in 
monstrous  blossoms.  Cases  of  the  kind  are  not  very  rare  in  Wil- 
lows, where  anthers  are  found  either  half  changed  or  else  perfectly 
transformed  into  pistils,  and  bearing  ovules  instead  of  pollen.  In 
gardens  some  stamens  of  the  common  Poppy  have  been  found 
changed  into  perfect  pistils,  and  imperfect  attempts  of  the  kind  are 
more  frequently  to  be  detected  in  the  large  Oriental  Poppy.  Two 
Apple-trees  in  Ashburnham,  Massachusetts,  have  long  been  known, 
which  annually  produce  flowers  in  which  the  petals  are  replaced  by 
five  small  foliaceous  bodies,  resembling  sepals,  and  in  place  of  sta- 
mens there  are  ten  separate  and  accessory  pistils,  inserted  on  the 
throat  of  the  calyx. 

428.  This  transformation  of  one  organ  into  another  is  called  met- 
amorphosis. Assuming  green  foliage  to  be  the  natural  state  of 
leaves,  the  sepals  and  petals  are  said  to  be  transformed  or  metamor- 
phosed leaves ;  and  the  stamens  and  pistils  are  still  more  metamor- 
phosed, losing  as  they  ordinarily  do  all  appearance  of  leaves.  Still, 
if  these  organs  be,  as  it  were,  leaves  developed  in  peculiar  states, 
under  the  controlling  agency  of  a  power  which  has  overborne  the 
ordinary  forces  of  vegetation,  they  must  always  have  a  tendency  to 

345  346  develop    in   their   primitive   form,  when   the 

causes  that  govern  the  production  of  blossoms 
are  interfered  with  during  their  formation. 
They  may  then  reverse  the  spell,  and  revert 
into  some  organ  below  them  in  the  series,  as 
from  stamens  into  petals,  or  pass  at  once  into 
the  state  of  ordinary  leaves.  That  is,  organs 
which  from  their  position  should  be  stamens 
or  pistils  may  develop  as  petals  or  floral 
leaves,  or  else  may  revert  at  once  to  the  state 
of  ordinary  leaves.  Such  cases  of  retrograde 
metamorphosis  frequently  occur  in  cultivated 
flowers. 

429.  Thus  we  often  meet  with  the  actual  reconversion  of  what 


FIG.  345.    A  small  leaf  in  place  of  a  pistil  from  the  centre  of  a  flower  of  the  double  Cherry. 
346.  An  organ  intermediate  between  a  leaf  and  a  pistil,  from  a  similar  flower. 
FIG.  347.    Leaflet  of  a  Brvophylluni,  developing  buds  along  its  margins. 


ITS    THEORETICAL    STRUCTURE. 


229 


should  be  a  pistil  into  a  leaf  in  the  double  Garden  Cherry,  either 
completely  (Fig.  345),  or  else  incompletely,  so  that  the  resulting 
organ  (as  in  Fig.  346)  is  something  intermediate  between  the  two. 
The  change  of  tvhat  should  be  stamens  into  petals  is  of  common  oc- 
currence in  what  are  called  double  and  semi-double  flowers  of  the 
gardens  ;  as  in  Roses,  Camellias,  Carnations,  &c.  When  such  flow- 
ers have  many  stamens,  these  disappear  as  the  supernumerary  petals 
increase  in  number ;  and  the  various  bodies  that  may  be  often  ob- 
served, intermediate  between  perfect  stamens  (if  any  remain)  and 
the  outer  row  of  petals,  —  from  imperfect  petals,  Avith  a  small  lamina 
tapering  into  a  slender  stalk,  to  those  which  bear  a  small  distorted 
lamina  on  one  side  and  a  half-formed  anther  on  the  other,  —  plainly 
reveal  the  nature  of  the  transformation  that  has  taken  place.  Car- 
ried a  step  farther,  the  pistils  likewise  disappear,  to  be  replaced  by 
a  rosette  of  petals,  as  in  fully  double  Buttercups. 

430.  In  full  double  Buttercups  we  may  often  notice  a  tendency 
in  the  inner  petals  to  turn 
green,  that  is,  to  retro- 
grade still  farther  into  foli- 
aceous  organs.  And  there 
is  a  monstrous  state  of  the 
Strawberry  blossom,  well 
known  in  Europe,  in  which 
all  the  floral  organs  revert 
into  green  sepals,  or  imper- 
fect leaves.  Fig.  348  ex- 
hibits a  similar  retrograde 
metamorphosis  in  a  flower 
of  the  "White  Clover,  where 
the  calyx,  pistil,  &c.  are 
still  recognizable,  although 
partially  transformed  into 
leaves.  And  the  ovary, 
which  has  opened  down  one 
side,  bears  on  each  edge  a  number  of  small  and  imperfect  leaves ; 
much  as  the  ordinary  leaves,  or  rather  leaflets,  of  Bryophyllum  are 
apt  to  develop  rudimentary  tufts  of  leaves,  or  leaf-buds,  on  their 
margins  (Fig.  347),  which  may  grow  into  little  plantlets,  by  which 
the  species  is  often  propagated.     This  retrograde  metamorphosis  of 

FIG.  348.    A  flower  of  the  common  White  Clover  reverting  to  a  leafy  branch; after  Turpin. 

20 


230 


THE   FLOWER. 


a  whole  blossom  into  foliaceous  parts  has  been  termed  chlorosis,  from 
the  green  color  thus  assumed. 

431.  A  somewhat  different  proof  that  the  blossom  is  a  sort  of 
branch,  and  its  parts  leaves,  is  occasionally  furnished  by  monstrous 
flowers  in  the  production  of  a  leafy  branch  from  the  centre  of  a  flower, 
or  of  one  flower  out  of  the  centre  of  another  (as  rose-buds  out  of 
roses).      Here  the  receptacle  or  axis  of  the  flower  resumes  the 

ordinary  vegetative 
growth,  as  in  Fig. 
349,  350.  In  wet 
and  warm  springs, 
some  of  the  flower- 
buds  of  the  Pear  and 
Apple  are  occasion- 
ally forced  into  vege- 
tation, so  as  com- 
pletely to  break  up 
the  flower  and  change 
it  into  an  ordinary 
leafy  branch.  This 
proves  that  the  recep- 
tacle of  a  flower  is  of  the  nature  of  the  stem. 

432.  An  analogous  kind  of  monstrosity,  viz. 
the  development  of  buds  —  either  into  leafy 
branches  or  into  blossoms  (Fig.  351) — in  the 
axils  of  petals,  or  even  of  stamens  or  pistils,  fur- 
nishes additional  evidence  that  these  bodies  are  of  the  nature  of 

leaves ;    for,  whatever   bears  a  bud   or 
branch  in  its  axil  must  represent  a  leaf. 

433.  The  irresistible  conclusion  from 
all  such  evidence  is,  that  the  flower  is 
one  of  the  forms  —  the  ultimate  form  — 
under  which  branches  appear ;  that  the 
leaves  of  the  stem,  the  leaves  or  petals 
of  the  flower,  and  even  the  stamens 
and  pistils,   are  all  forms  of  a    common 

FIG.  S49.  Retrograde  metamorphosis  of  a  flower  of  the  Fraxinella  of  the  gardens,  from 
Lindley  "s  Theory  of  Horticulture ;  an  internode  elongated  just  above  the  stamens,  and  bearing 
a  whorl  of  green  leaves. 

FIG.  350.     A  monstrous  pear,  prolonged  into  a  leafy  branch  ;  from  Bonnet. 

FIG.  351.  A  flower  of  False  Bittersweet  (Celastrus  scandens),  producing  other  flowers  in 
the  axils  of  the  petals ;  from  Turpin. 


ITS    THEORETICAL    STRUCTURE.  231 

type,  only  differing  in  their  special  development.  And  it  may 
be  added,  that  in  an  early  stage  of  development  they  all  appear 
nearly  alike.  That  which,  under  the  ordinary  laws  of  vegetation, 
would  have  developed  as  a  leafy  branch,  here  developes  as  a  flower ; 
its  several  organs  appearing  under  forms,  some  of  them  slightly,  and 
others  extremely,  different  in  aspect  and  in  office  from  the  foliage. 
But  they  all  have  a  common  nature  and  a  common  origin,  or,  in 
other  words,  are  homologous  parts  (424). 

434.  Now,  as  we  have  no  general  name  to  comprehend  all  those 
organs  which,  as  foliage,  bud-scales,  bracts,  sepals,  petals,  stamens, 
&c,  successively  spring  from  the  ascending  axis  or  stem,  having  ascer- 
tained their  essential  identity,  we  naturally  take  some  one  of  them 
as  the  type,  and  view  the  others  as  modifications  or  metamorphoses 
of  it.  The  leaf  is  the  form  which  earliest  appears,  and  is  the  most 
general  of  all  the  organs  of  the  vegetable  ;  it  is  the  form  which  is 
indispensable  to  normal  vegetation,  since  in  it,  as  we  have  seen,  as- 
similation is  effected,  and  all  organic  matter  is  produced ;  it  is  the 
form  into  which  all  the  floral  organs  may  sometimes  be  traced  back 
by  numerous  gradations,  and  to  which  they  are  liable  to  revert  when 
flowering  is  disturbed  and  the  vegetative  forces  again  prevail. 
Hence  the  leaf  may  be  properly  assumed  as  the  type  or  pattern,  to 
which  all  the  others  are  to  be  referred.  When,  therefore,  the  floral 
organs  are  called  modified  or  metamorphosed  leaves,  it  is  not  to  be 
supposed  that  a  petal  has  ever  actually  been  a  green  leaf,  and  has 
subsequently  assumed  a  more  delicate  texture  and  hue,  or  that  sta- 
mens and  pistils  have  previously  existed  in  the  state  of  foliage  ;  but 
only  that  what  is  fundamentally  one  and  the  same  organ  develops, 
in  the  progressive  evolution  of  the  plant,  under  each  or  any  of 
these  various  forms.  When  the  individual  organ  has  developed,  its 
destiny  is  fixed. 

435.  The  theory  of  vegetable  morphology  may  be  expressed  in 
other  and  more  hypothetical  or  transcendental  forms.  We  have 
preferred  to  enunciate  it  in  the  simplest  and  most  general  terms. 
But,  under  whatever  particular  formula  expressed,  its  adoption  has 
not  only  greatly  simplified,  but  has  thrown  a  flood  of  light  over  the 
whole  of  Structural  Botany,  and  has  consequently  placed  the  whole 
logic  of  Systematic  Botany  upon  a  new  and  philosophical  basis. 
Our  restricted  limits  will  not  allow  us  to  trace  its  historical  develop- 
ment. Suffice  it  to  say,  that  the  idea  of  the  essential  identity  of  the 
floral  organs  and  the    leaves  was    distinctly  propounded  by   Lin- 


232  THE    FLOWER. 

nteus,*  about  the  middle  of  the  last  century.  It  was  newly  taught 
by  Caspar  Frederic  Wolff,  about  twenty  years  later,  and  again,  after 
the  lapse  of  nearly  twenty  years  more,  by  the  celebrated  Goethe, 
who  was  entirely  ignorant,  as  were  his  scientific  contemporaries,  of 
what  Linnreus  and  Wolff  had  written  on  the  subject.  Goethe's 
curious  and  really  scientific  treatise  was  as  completely  forgotten  or 
overlooked  as  the  significant  hints  of  Linnaeus  had  been.  In  ad- 
vance of  the  science  of  the  day,  and  more  or  less  encumbered  with 
hypothetical  speculations,  none  of  these  writings  appear  to  have  ex- 
erted any  appreciable  influence  over  the  progress  of  the  science, 
until  it  had  reached  a  point,  early  in  the  present  century,  when  the 
nearly  simultaneous  generalizations  of  several  botanists,  following 
different  clews,  were  leading  to  the  same  conclusions.  Ignorant  of 
the  writings  of  Goethe  and  Wolff,  De  Candolle  was  the  first  to  de- 
velop, from  an  independent  and  original  point  of  view,  the  idea  of 
symmetry  in  the  flower ;  that  the  plan,  or  type,  of  the  blossom  is 
regular  and  symmetrical,  but  that  this  symmetry  is  more  or  less  in- 
terfered with,  modified,  or  disguised  by  secondary  influences,  such  as 
suppressions,  alterations,  or  irregularities,  giving  rise  to  the  greatest 
diversity  of  forms.  The  reason  of  the  prevailing  symmetrical  ar- 
rangement of  parts  in  the  blossom  has  only  recently  been  made 
apparent,  in  the  investigation  of  phyllotaxis  (236)  ;  from  which  it 
appears  that  the  general  arrangement  of  the  leaves  upon  the  stem 
is  carried  out  in  the  flower. 


Sect.  III.     The  Symmetry  of  the  Flower. 

436.  A  Symmetrical  Flower  is  one  which  has  an  equal  number  of 
parts  in  each  circle  or  whorl  of  organs  ;  as,  for  example,  in  Fig. 
334,  where  there  are  five  sepals,  five  petals,  five  stamens,  and  five 
pistils.  It  is  not  less  symmetrical,  although  less  simple,  when  there 
are  two  or  more  circles  of  the  same  kind  of  organ ;  as  in  Sedum 
(Fig.  361),  where  there  are  two  sets  of  stamens,  five  in  each;  in 
the  Barberry,  where  there  are  two  or  more  sets  of  sepals,  two  of 
petals,  and  two  of  stamens,  three  in  each  set,  &e.     A  complete  floioer 

*  "  Principium  florum  etjbliorum  idem  est.  Principium  gemmarum  et  folio- 
rum  idem  est.  Gemma  constat  folioram  rudimentis.  Pcrianthium  sit  ex  con- 
iiatis  foliorum  rudimentis,"  etc.     Philosophia  Botanica,  p.  301. 


ITS    SYMMETRY. 


233 


of  floral 
stamens 


(as  already  defined,  416)  is  one  that  possesses  both  sorts 
envelopes,  calyx  and  corolla,  and  both  essential  organs,  viz. 
and  pistils. 

437.  The  simplest  possible  complete  and 
symmetrical  flower  would  be  one  with  the  ca- 
lyx of  a  single  sepal,  a  corolla  of  a  single  petal, 
a  single  stamen,  and  a  single  pistil ;  as  in  the 
annexed  diagram  (Fig.  352),  which  represents 
the  elements  of  a  simple  stem  (Fig.  157),  ter- 
minated by  an  equally  simple  flower.  Each 
constituent  of  the  blossom  represents  a  phyton 
(1G3),  with  its  stem  part  reduced  to  a  mini- 
mum, and  its  leaf  part  developed  in  a  peculiar 
way,  according  to  the  rank  it  sustains  and  the 
office  it  is  to  fulfil.  That  there  are  short  inter- 
nodes  between  consecutive  organs  in  the  flower 
is  usually  apparent  on  minute  inspection  of  its 
axis,  or  receptacle  ;  and  some  of  them  are  con- 
spicuously prolonged  in  certain  cases.  But 
they  are  commonly  so  short  that  the  organs 
are  brought  into  juxtaposition,  just  as  in  a  leaf- 
bud,  and  the  higher  or  later-formed  parts  are 
interior  or  enclosed  by  the  lower. 

438.  Perhaps  the  exact  case  of  a  flower  at 
once  so  complete  and  so  simple  is  not  to  be  met 
with,  the  organs  of  the  flower,  or  some  of 
them,  being  generally  multiplied.  Thus  we 
find  a  circle  or  whorl  of  each  kind  of  organ, 
and  often  two  or  three  circles,  or  a  still  larger 
and  apparently  indefinite  number  of  parts.  In 
fact,  the  floral  organs  usually  occur  in  twos, 
threes,  fours,  or  fives  ;  and  the  same  number 
is  apt  to  prevail  throughout  the  several  circles 
of  the  flower,  which  therefore  displays  a  sym-  352 
metrical  arrangement,  or  a  manifest  tendency  towards  it* 


*  Terms  expressive  of  the  number  of  parts  which  compose  each  whorl  or 
kind  of  organ  —  which  are  sometimes  very  convenient  to  use  —  arc  formed  of 

FIG.  352.  Diagram  of  a  plant,  with  a  distichous  arrangement  of  the  phytons,  carried 
through  the  complete  flower,  of  the  simplest  kind,  consisting  of,  a,  a  sepal  j  b,  a  petal  j  c,  a 
stamen  ;  and  d,  a  pistil :  br  is  the  bract  or  uppermost  proper  leaf. 

20* 


234 


THE    FLOWER. 


430.  Having  already  noticed  the  symmetrical  arrangement  of  the 
foliage  (236-251),  and  remarked  the  transition  of  ordinary  leaves 

into  those  of  the  blossom 
(426),  we  naturally  seek 
to  bring  the  two  under 
the  same  general  laws, 
and  look  upon  each  floral 
whorl  as  answering  ei- 
ther to  a  cycle  of  alter- 
nate leaves  with  their  33i 
respective  internodes  undeveloped, 
or  to  a  pair  or  verticil  of  opposite 
or  verticillate  leaves.  Thus,  the  simplest  com- 
bination, where  the  organs  are  dimerous,  or  in 
twos,  may  be  compared  with  the  alternate  two- 
ranked  arrangement  (238),  the  calyx,  the  corolla, 
stamens,  &c.  each  consisting  of  one  cycle  of  two 
elements  ;  or  else  with  the  case  of  opposite  leaves 
(250),  when  each  set  would  answer  to  a  pair  of 
leaves.  So,  likewise,  the  organs  of  a  trimerous 
flower  (viz.  one  with  its  parts  in  threes,  as  in  Fig. 
353)  may  be  taken  either  as  cycles  of  alternate 
leaves  of  the  tristichous  mode  (239),  with  the  axis 
shortened,  which  would  throw  the  parts  into  successive  whorls  of 
threes,  or  else  as  proper  verticils  of  three  leaves  ;  while  those  of  a 
pentamerous  or  quinary  flower  (with  the  parts  in  fives,  as  in  Fig.  354) 
would  answer  to  the  cycles  of  the  §  arrangement  (240)  of  alternate 
leaves,  or  to  proper  five-leaved  verticils.  So  the  whorls  of  a  tetra- 
merous  flower  are  to  be  compared  with  the  case  of  decussating  op- 


the  Greek  numerals  combined  with  fiepos,  a  part.  Thus  a  flower  with  only  one 
organ  of  each  kind,  as  in  the  diagram,  Fig.  352,  is  mo/wmerous :  a  flower  or  a 
whorl  of  two  organs  is  dimerous  (Fig.  373) ;  of  three  (as  in  Fig.  353),  trimerous ; 
of  four,  tetramerous  (Fig.  405) ;  of  five  (as  in  Fig.  334),  pentamerous  ;  of  six,  hex- 
amcrous  ;  of  ten,  ckeamcrous,  &c.  These  words  arc  often  printed  with  figures,  as 
2-merous,  S-merous,  A-merous,  5-merous,  and  so  on. 

FIG.  353.    Parts  of  a  symmetrical  trimerous  flower  (Tillsea  muscosa) :  a,  calyx  ;  b,  corolla  ; 

c,  stamens  ;  d.  pistils. 

FIG.  354.  Ideal  plan  of  a  plant,  with  the  simple  stem  terminated  by  a  symmetrical  penta- 
merous flower ;  the  different  sets  of  organs  separated  to  some  distance  from  each  other,  to  show 
the  relative  situation  of  the  parts ;  one  of  each,  namely,  o,  a  sepal,  6,  a  petal,  c,  a  stamen,  and 

d,  a  pistil,  also  shown,  enlarged. 


ALTERNATION    OF    THE    FLORAL    ORGANS.  235 

posite  leaves,  combined  two  by  two,  or  with  quaternary  verticillate 
leaves  (251)  ;  either  of  which  would  give  sets  of  parts  in  fours. 

440.  The  Alternation  of  the  Floral  Organs.  We  learn  from  obser- 
vation that,  as  a  general  rule,  the  parts  of  the  successive  circles  of 
the   flower   alternate    with    each   other.     The  five 

petals  of  the  flower  represented  in  Fig.  334,  for  ex- 
ample, are  not  opposed  to  the  five  sepals  (that  is, 
situated  directly  above  or  before  them),  but  alter- 
nate with  them,  that  is,  or  stand  over  the  intervals 
between  them ;  the  five  stamens  in  like  manner  al- 
ternate with  the  petals,  and  the  five  pistils  with  the 
stamens,  as  is   shown  in  the   diagram,  Fig.  335.     The  same  is  the 
case  in  Fig.  353,  the  several  organs   of  a  flower  Avith  its  parts  in 
threes  ;  and  in  fact  this  is  the  rule,  the  few  exceptions   to   which 
have  to  be  separately  accounted  for. 

441.  This  comports  with  the  more  usual  phyllotaxis  in  opposite 
and  verticillate  leaves,  where  the  successive  pairs  decussate,  or  cross 
each  other  at  right  angles  (251),  or  the  leaves  of  one  verticil  several- 
ly correspond  to  the  intervals  of  that  underneath,  making  twice  as 
many  vertical  ranks  as  there  are  parts  in  the  whorl.  The  alternation 
of  the  floral  organs  is  therefore  most  readily  explained  on  the  assump- 
tion that  the  several  circles  are  true  decussating  verticils.  But  the 
inspection  of  a  flower-bud  with  the  parts  imbricated  in  aestivation 
(494)  shows  that  the  several  members  of  the  same  set  do  not  origi- 
nate exactly  in  the  same  plane.  The  five  petals,  for  example,  in 
the  cross-section  of  the  pentamerous  blossom  shown  in  Fig.  335  (and 
the  same  arrangement  is  still  more  frequently  seen  in  the  calyx), 
are  so  situated,  that  two  are  exterior  in  the  bud,  and  therefore  in- 
serted lower  on  the  axis  than  the  rest,  the  third  is  intermediate,  and 
two  others  are  entirely  interior,  or  inserted  higher  than  the  rest.  In 
fact,  they  exactly  correspond  with  a  cycle  of  alternate  leaves  of  the 
quincuncial  or  five-ranked  arrangement,  on  an  extremely  abbreviated 
axis,  or  on  a  horizontal  plane,  as  is  at  once  seen  by  comparing  the 
ground  plan,  Fig.  335,  with  Fig.  206.  Compare  also  Fig.  355  with 
Fig.  203.  Also,  when  the  parts  are  in  fours,  two  are  almost  always 
exterior  in  the  bud,  and  two  interior.  Moreover,  whenever  the 
floral  envelopes,  or  the  stamens  or  pistils,  are  more  numerous,  so  as 
to  occupy  several  rows,  the  spiral  disposition  is  the  more  manifest. 
It  is  most  natural,  accordingly,  to  assume  that  the   calyx,  corolla, 

FIG.  355.     Cross-section  of  the  flower-bud  of  Fig.  353,  to  show  the  alternation  of  parts. 


236  THE    FLOWER. 

stamens,  &c.  of  a  pentamerous  flower  are  each  a  depressed  spiral  or 
cycle  of  the  §  mode  of  phyllotaxis,  and  those  of  the  trimerons  flower 
are  similar  spirals  of  the  £  mode.  But  then  the  parts  of  the  suc- 
cessive cycles  should  be  superposed,  or  placed  directly  before  each 
other  on  the  depressed  axis,  as  leaves  are  ;  whereas,  on  the  contrary, 
they  almost  always  alternate  with  each  other  in  the  flower. 

442.  To  reconcile  this  alternation  with  the  laws  of  phyllotaxis  in 
alternate  leaves,  Prof.  Adrien  de  Jussieu  has  advanced  an  ingenious 
hypothesis.  lie  assumes  the  T53  spiral  arrangement  as  the  basis  of 
the  floral  structure  both  of  the  trimerous  and  pentamerous  flower, 
(at  least  when  the  envelopes  are  imbricated  in  the  bud,)  this  being 
the  one  that  brings  the  successive  parts  most  nearly  into  alternation, 
either  in  threes  or  in  fives ;  as  will  readily  be  observed  on  inspection 
of  the  tabular  projection  of  that  mode,  given  on  page  139.  The  dif- 
ference between  the  position  of  parts  in  regular  alternation,  Avhether 
in  threes  or  fives,  and  that  assigned  by  an  accurate  spiral  projection 
of  the  T55  mode,  is  very  slight  as  respects  most  of  the  organs,  and  in 
none  does  the  deviation  exceed  one  thirteenth  of  the  circumference ; 
—  a  quantity  which  becomes  nearly  insignificant  on  an  axis  so  small 
as  that  of  most  flowers.  Moreover,  if  the  interior  organs  of  a  regular 
and  symmetrical  flower  were  thus  to  originate  in  the  bud  nearly  in 
alternation  with  those  that  precede  them,  they  would  almost  necessa- 
rily be  crowded  a  little,  as  they  develop,  into  the  position  of  least  pres- 
sure, and  thus  fall  into  these  intervals  with  all  the  exactness  that  is 
actually  found  in  nature.  For  in  living  bodies,  endowed  as  they  are 
with  plasticity  and  a  certain  power  of  adaptation  to  circumstances, 
the  positions  assumed  are  not  mathematically  accurate ;  and  the 
effect  of  unequal  pressure  in  the  bud  in  throwing  the  smaller  parts 
more  or  less  out  of  their  normal  position  may  be  observed  in  almost 
any  irregular  flower.  Moreover,  in  all  the  forms  of  phyllotaxis 
from  T5g-  onwards,  it  is  doubtful  whether  what  we  term  vertical  ranks 
are  exactly  superposed.  In  tracing  them  upward  to  some  extent, 
we  perceive  indications  of  a  curviserial  arrangement,  where  the 
superposition  is  continually  approximated,  but  is  never  exactly  at- 
tained (248).  Lestibudois*  has  revived  the  older  hypothesis  of 
Jussieu,  and  others  ;  viz.  that  a  second  spiral  is  introduced  with  the 
petals  and  continued  in  the  pistils.  And  Schimper  and  Braun  im- 
agine a  change  of  half  the  angular  divergence  (prosenthesis)  to  occur 

*  In  Annates  des  Sciences  Naturelles,  ser.  4,  Vol.  2,  p.  226. 


POSITION    IN   RESPECT    TO    THE    BRACT    AND    AXIS. 


237 


in  passing  from  one  cycle  to  the  next ;  —  which  is  rather  describing 
the  anomaly  in  other  words  than  explaining  it. 

443.  Whether  we  regard  the  floral  circles  as  decussating  verticils, 
or  as  cycles  of  alternate  leaves  in  some  way  altered  as  to  their  suc- 
cession, we  cannot  fail  to  discern  an  end  attained  by  such  arrange- 
ment, namely,  a  disposition  of  parts  which  secures  the  greatest  econ- 
omy of  space  on  an  abbreviated  axis,  and  the  greatest  freedom  from 
mutual  pressure. 

444.  Position  of  the  Flower  as  respects  the  Axis  and  subtending  Bract. 

All  axillary  flowers  are  situated  between  a  leaf  and  the  stem,  or, 
which  is  the  same  thing,  between  a  bract  and  the  axis  of  inflores- 
cence. These  two  fixed  points  enable  us  to  indicate  the  relative 
position  of  the  parts  of  the  floral  circles  with  precision.  That  part 
of  the  flower  which  lies  next  the  leaf  or  bract  from  whose  axil  it 
arises  is  said  to  be  anterior,  or  inferior  (lower)  :  that  which  is  dia- 
metrically opposite  or  next  the  axis  is  posterior,  or  superior  (upper).* 


It  is  important  to  notice  the  relative  position  of  parts  in  this  re- 
spect. This  is  shown  in  a  proper  diagram  by  drawing  a  section 
of  the  bract  in  its  true  position  under  the  section  of  the  flower- 
bud,  as  in  Fig.  358  :  the  position  of  the  axis  is  necessarily  dia- 
metrically opposite,  and  its  section  is  sometimes  indicated  by  a  dot 
or  small  circle.     In  an  axillary  flower  with  the  parts  hi  fours,  one  of 


*  As  if  these  were  not  terms  enough,  sometimes  the  organ,  or  side  of  the 
flower,  which  looks  towards  the  bract,  is  likewise  called  exterior,  and  the  organ 
or  side  next  the  axis,  interior ;  but  these  terms  should  be  kept  to  designate  the 
relative  position  of  the  members  of  the  floral  circles  in  aestivation  (494). 

FIG.  356.  Diagram  of  a  Cruciferous  flower  (Erysimum) ;  a,  the  axis  of  inflorescence.  (The 
bract  is  abortive  in  this,  as  in  most  plants  of  this  family.) 

FIG.  357.  Diagram  of  a  flower  of  a  Rhus,  with  the  axis,  a,  and  the  bract,  b,  to  show  the 
relative  position  of  parts. 

FIG.  358.     Diagram  of  a  flower  of  the  Pulse  tribe :  a,  the  axis,  and  0,  the  bract. 


238  THE    FLOWER. 

the  sepals  will  be  anterior,  one  posterior,  and  two  lateral,  or  right 
and  left ;  as  in  the  annexed  diagram  of  a  Cruciferous  blossom  (Fig. 
356)  ;  while  the  petals,  alternating  with  the  sepals,  consist  of  an 
anterior  and  a  posterior  pair ;  and  the  stamens,  again,  stand  before 
the  sepals.  An  axillary  flower  of  five  parts  will  have  either  one 
sepal  superior  or  posterior  and  two  inferior  or  anterior  (as  in  Rhus, 
Fig.  357),  or  else,  vice  versa,  one  inferior  and  two  superior,  as  in 
Papilionaceous  flowers  (Fig.  358) :  in  both  cases  the  two  remaining 
sepals  are  lateral.  The  petals  will  consequently  stand  one  superior, 
two  inferior,  and  two  lateral,  in  the  last-named  case ;  and  one  in- 
ferior, two  superior,  and  two  lateral,  in  the  former.  In  terminal 
flowers  (401),  the  position  of  parts  in  respect  to  the  uppermost 
leaves  or  bracts  should  be  noted. 


Sect.  IV.    The  Various  Modifications  of  the  Flower. 

445.  The  complete  and  symmetrical  flowers,  with  all  their  organs 
in  the  most  normal  state,  that  have  now  been  considered,  will  serve 
as  the  type  or  pattern,  with  which  Ave  may  compare  the  almost  num- 
berless variety  of  forms  which  blossoms  exhibit,  and  note  the  char- 
acter of  the  differences  observed.  We  proceed  upon  the  supposi- 
tion, that  all  flowers  are  formed  upon  a  common  plan,  —  a  plan 
essentially  the  same  as  that  of  the  stem  or  branch,  of  which  the 
flower  is  a  modified  continuation,  —  so  that  in  the  flower  Ave  are  to 
expect  no  organs  other  than  those  that,  Avhatever  their  form  and 
office,  ansAver  either  to  the  axis  or  to  the  leaves  ;  so  that  the  differ- 
ences between  one  flower  and  another  are  to  be  explained  as  cir- 
cumstantial variations  of  one  fundamental  plan,  —  variations  for  the 
most  part  analogous  to  those  Avhich  occur  in  the  organs  of  vegeta- 
tion themselves.  Having  assumed  the  type  which  represents  our 
conception  of  the  most  complete,  and  at  the  same  time  the  simplest 
floAver,  Ave  apply  it  to  all  the  cases  Avhich  present  themselves,  and 
especially  to  those  blossoms  in  Avhich  the  structure  and  symmetry 
are  masked  or  obscured ;  Avhere,  like  the  disenchanting  spear  of 
Ithuriel,  its  application  at  once  reveals  the  real  character  of  the  most 
disguised  and  complicated  forms  of  structure. 

446.  Our  pattern  floAver  consists  of  four  circles,  one  of  each  kind  of 
floral  organ,  and  of  an  equal  number  of  parts,  successively  alternat- 
ing Avith  one  another.     It  is  complete,  having  both  calyx  and  corolla, 


ITS    VARIOUS    MODIFICATIONS.  239 

as  well  as  stamens  and  pistils  (41 G)  ;  symmetrical,  having  an  equal 
number  of  parts  in  the  successive  whorls  (43  G)  ;  regular,  in  having 
the  different  members  of  each  circle  all  alike  in  size  and  shape ;  it 
has  but  one  circle  of  the  same  kind  of  organs  ;  and,  moreover,  all  the 
parts  are  distinct  or  unconnected,  so  as  to  exhibit  their  separate 
origin  from  the  axis  or  receptacle  of  the  flower.  This  type  may  be 
presented  under  either  of  the  four  numerical  forms  which  have  been 
illustrated.  That  is,  its  circles  may  consist  of  parts  in  twos  (when 
it  is  binary  or  dimerous),  threes  (ternary  or  trimerous),  fours  (qua- 
ternary or  tetramerous),  or  fives  (quinary  or  pentamerous).  The 
first  of  these  is  the  least  common;  the  trimerous  and  the  pentame- 
rous far  the  most  so.  The  last  is  restricted  to  Dicotyledonous  plants, 
where  five  is  the  prevailing  number ;  while  the  trimerous  flower 
largely  prevails  in  Monocotyledonous  plants,  although  by  no  means 
wanting  in  the  Dicotyledonous  class,  from  which  Fig.  353  is  taken. 

447.  The  principal  deviations  from  the  perfectly  normal  or 
pattern  flower  may  be  classified  as  follows.  They  arise,  either 
from,  — 

1st.  The  production  of  additional  circles  of  one  or  more  of  the 
floral  organs  (regular  multiplication  or  augmentation)  ; 

2d.  The  production  of  a  pair  or  a  cluster  of  organs  where  there 
should  normally  be  but  one,  that  is,  the  multiplication  of  an  organ 
by  division  (abnormal  multiplication,  also  termed  deduplication  or 
chorisis)  ; 

3d.  The  anteposition  (or  opposition,  instead  of  alternation)  of  the 
parts  of  successive  circles ; 

4th.  The  union  of  the  members  of  the  same  circle  (coalescence)  ; 

5th.  The  union  of  adjacent  parts  of  different  circles  (adnation)  ; 

Gth.  The  unequal  growth  or  unequal  union  of  different  parts  of 
the  same  circle  [irregularity)  ;  or, 

7th.  The  non-production  or  abortion  of  some  parts  of  a  circle,  or 
of  one  or  more  complete  circles  (suppression  or  abortion). 

8th.  To  which  may  be  added,  the  abnormal  development  of  the 
receptacle  or  axis  of  the  flower. 

448.  Some  of  these  deviations  interfere  with  the  symmetrical 
structure  of  the  flower  ;  others  merely  render  it  irregular,  or  dis- 
guise the  real  origin  or  the  real  number  of  parts.  These  deviations, 
moreover,  are  seldom  single  ;  but  two,  three,  or  more  of  the  kinds  fre- 
quently co-exist,  so  as  to  realize  almost  every  conceivable  variation. 

449.  Several  of  these  kinds  of  deviation  may  often  be  observed 


240 


THE    FLOWER. 


$$to 


o 


even  in  the  same  natural  family  of  plants,  where  it  cannot  be  doubt- 
ed that  the  blossoms  are  constructed  upon  a  common  plan  in  all  the 
species.  Even  in  the  family  Crassulaceae,  for  example,  where  the 
flowers  are  remarkably  symmetrical,  and  from 
which  our  pattern  flowers,  Fig.  334  and  353, 
are  derived,  a  considerable  number  of  these  di- 
versities are  to  be  met  with.  In  Crassula,  we 
have  the  completely  symmetrical  and  simple 
pentamerous  flower  (Fig.  359,  3G0),  viz.  with  a 
calyx  of  five  sepals,  a  corolla  of  five  petals  alter- 
nate with  the  former,  an  andrcecium  (418)  of 
five  stamens  alternating  with  the  petals,  and  a 
gynsecium  (419)  of  five  pistils,  which  are  alter- 
nate with  the  stamens  ;  and  all  the  parts  are 
regular  and  symmetrical,  and  also  distinct  and 
free  from  each  other ;  except  that  the  sepals  are 
somewhat  united  at  the  base,  and  the  petals  and 
360  stamens  slightly  connected  with  the  inside  of  the 

calyx,  instead  of  arising  directly  from  the  recep- 
tacle or  axis,  just  beneath  the  pistils.  Five  is  the  prevailing  or 
normal  number  in  this  family.  Nevertheless,  in  the  related  genus 
Tillrea,  most  of  the  species,  like  ours  of  the  United  States,  have 
their  parts  in  fours,  but  are  otherwise  similar,  and  one  common 
European  species  has  its  parts  in  threes  (Fig.  353)  ;  that  is,  one  or 
two  members  are  left  out  of  each  circle,  which  of  course  does  not  in- 
terfere with  the  symmetry  of  the  blossom.  So  in  the  more  conspic- 
uous genus  Sedum  (the  Stonecrop,  Live-for-ever,  Orpine,  &c),  some 
species  have  their  parts  in  fives  ;  others 
in  fours  ;  and  several,  like  our  S.  ter- 
natum,  have  those  of  the  first  blossom 
in  fives,  but  all  the  rest  in  fours.  But 
Sedum  also  illustrates  the  case  of  reg- 
ular augmentation  (447, 1st)  in  its  an- 
droecium,  which  consists  of  twice  as 
many  stamens  as  there  are  members 
in  the  other  parts  ;  that  is,  an  addi-  361 

tional  circle  of  stamens  is  introduced  (Fig.  361),  the  members  of 
which  may  be  distinguished  by  being  shorter  or  a  little  later  than 


FIG.  359.    Flower  of  a  Crassula.    360.  Cross-section  of  the  bud. 
FIG.  361.     Flower  of  a  Sedum  or  Stonecrop. 


ITS    VARIOUS    MODIFICATIONS. 


241 


those  of  the  primary  circle,  and  by  their  alternation  with  these, 
which  brings  them  directly  opposite  the  petals.  A  third  genus 
(Rochea)  exhibits  the  same  pentamerous  and  normal  flower  as  Cras- 
sula,  except  that  the  contiguous  edges  of  the  petals  slightly  cohere 
about  half  their  length,  although  a  little  force  suffices  to  separate 
them:  in  another  (Grammanthes,  Fig.  362),  the  petals  are  firmly 
united  into  a  tube  for  more  than  half  their  length,  and  so  are  the 
sepals  likewise ;  illustrating  the  fourth  of  the  deviations  above 
enumerated  (447).  Next,  the  allied  genus  Cotyledon  (Fig.  363) 
exhibits  in  the  same  flower  both  this  coalescence  of  similar  parts, 
and  an  additional  circle  of  stamens,  as  in  Sedum.  It  likewise  pre- 
sents the  next  order  of  deviations,  in  the  union  (adnation)  of  the 
base  of  its  stamens  to  the  base  of  the  corolla,  out  of  which  they  ap- 
parently arise,  as  is  seen  in  Fig.  364,  where  the  corolla  is  laid  open 
and  displayed.  The  pistils,  although  ordinarily  exhibiting  a  strong 
tendency  to  unite,  are  perfectly  distinct  in  all  these  cases,  and  in- 
deed throughout  the  order,  with  two  exceptions  ;  one  of  which  is 
seen  in  Penthorum,  where  the  five  ovaries  (Fig.  365)  are  united 
below  into  a  solid  body,  while  their  summits,  as  well  as  the  styles, 
are  separate.  The  same  jdant  also  furnishes  an  example  of  the  non- 
production  (or  supjyression)  of  one  set  of  organs,  that  of  the  petals  ; 
which,  although  said  to  exist  in  some  specimens,  are  ordinarily  Avant- 
ing  altogether.  Another  instance  of  increase  in  the  number  of  parts 
occurs  in  the  Houseleek  (Sempervivum),  in  which  the  sepals,  petals, 
and  pistils  vary  in  different  species  from  six  to  twenty,  and  the  sta- 
mens from  twelve  to  forty. 


450.  Some  illustrations  of  the  principal  diversities  of  the  flower, 

FIG.  362.  Flower  of  Grammanthes.  363.  Flower  of  a  Cotyledon.  361.  The  corolla  laid 
open,  showing  the  two  rows  of  stamens  inserted  into  it.  365.  The  five  pistils  of  Penthorum, 
united.     366.  A  cross-section  of  the  same. 

21 


242  THE    FLOWER. 

as  classified  above  (447),  may  be  drawn  at  random  from  different 
families  of  plants ;  and  most  of  the  technical  terms  necessarily  em- 
ployed in  describing  these  modifications  may  be  introduced,  and 
explained,  as  we  proceed.  The  multiplication  of  parts  is  usually  in 
consequence  of  the 

451.  Augmentation  of  the  Floral  Circles.    An  increased  number  of 

circles  or  parts  of  all  the  floral  organs  occurs  in  the  Magnolia 
family ;  where  the  floral  envelopes  occupy  three  or  four  rows,  of 
three  leaves  in  each,  to  be  divided  between  the  calyx  and  corolla, 
while  the  stamens  and  pistils  are  very  numerous,  and  compactly 
arranged  on  the  elongated  receptacle.  Tbe  Custard- Apple  family, 
which  is  much  like  the  last,  has  also  two  circles  in  the  corolla,  three 
petals  in  each,  a  great  increase  in  the  number  of  stamens,  and,  in 
our  Papaw  (Fig.  654),  sometimes  only  one  circle  of  pistils,  viz. 
three,  sometimes  twice,  thrice,  or  as  many  as  five  times  that  number. 
The  Water-Lily,  likewise,  has  all  its  parts  augmented,  the  floral 
envelopes  and  the  stamens  especially  occupying  a  great  number  of 
rows  ;  and  the  pistils  are  likewise  numerous,  although  their  number 
is  disguised  by  being  united  into  one  body.  "When  the  sepals,  petals, 
or  other  parts  of  the  flower  are  too  numerous  to  be  readily  counted, 
or  even  exceed  twelve,  especially  when  the  number  is  inconstant,  as 
it  commonly  is  in  such  cases,  they  are  said  to  be  indefinite  ;  and 
a  floAver  with  numerous  stamens  is  also  termed  polyandrous. 

452.  WTien  such  multiplication  of  the  floral  circles  is  perfectly 
regular,  the  number  of  the  organs  so  increased  is  a  multiple  of  that 
which  forms  the  basis  of  the  flower  ;  but  this  could  scarcely  be  de- 
termined when  the  numbers  are  large,  as  in  the  stamens  of  a  Butter- 
cup, for  example,  nor  is  there  much  constancy  when  the  whorls  of 
any  organ  exceed  three  or  four.  The  doubling  or  trebling  of  any 
or  all  the  floral  circles  does  not  interfere  with  the  symmetry  of  the 
flower ;  but  it  may  obscure  it  (in  the  stamens  and  pistils  especially), 
by  the  crowding  of  two  or  more  circles  of  five  members  into  what 
appears  like  one  of  ten,  or  two  trimerous  circles  into  what  appears 
like  one  of  six.     The  latter  case  occurs  in  most  Endogenous  plants. 

453.  The  production  of  additional  floral  circles  may  account  for 
most  cases  of  increase  of  the  normal  number  of  organs,  but  not  for 
all  of  them.  It  must,  we  think,  be  admitted  that  certain  parts  of  the 
blossom  are  sometimes  increased  in  number  by  the  production  of  a 
double  organ,  or  a  pair  or  a  group  of  organs  which  occupy  the  place 
of  one  ;  namely,  by  what  has  been  termed 


CHORISIS    OR    DEDUPLICATION. 


243 


454.  CJlOl'isis  Or  Deduplication.  The  name  dedoublement  of  Dunal, 
which  has  been  translated  deduplication,  literally  means  unlining ; 
the  original  hypothesis  being,  that  the  organs  in  question  unline,  or 
tend  to  separate  into  two  or  more  layers,  each  having  the  same 
structure.  We  may  employ  the  word  deduplication,  in  the  sense 
of  the  doubling  or  multiplication  of  the  number  of  parts,  without 
adopting  this  hypothesis  as  to  the  nature  of  the  process,  which  at 
best  can  well  apply  only  to  some  special  cases.  The  word  chorisis 
(xwpto-ty,  the  act  or  state  of  separation  or  multiplication),  also  pro- 
posed by  Dunal,  does  not  involve  any  such  assumption,  and  is  ac- 
cordingly to  be  preferred.  By  regular  multiplication,  therefore,  we 
mean  the  augmentation  of  the  number  of  organs  through  the  de- 
velopment of  additional  circles  ;  which  does  not  alter  the  symmetry 
of  the  flower.  By  chorisis  we  denote  the  production  of  two  or  more 
organs  in  the  place  of  one,  in  a  manner  analogous  to  the  division  of 
the  blade  of  a  leaf  into  a  number  of  separate  blades,  or  leaflets. 

455.  Chorisis,  or  the  division  of  an  organ  into  a 
pair  or  a  cluster,  may  take  place  in  two  ways. 
In  one  case  the  parts  or  organs  thus  produced 
stand  one  before  the  other  ;  in  the  other  case  they 
stand  side  by  side.  The  first  is  named  transverse 
chorisis  ;  the  second,  collateral  chorisis.  Both 
must  evidently  disturb  or  disguise  the  normal 
symmetry  of  the  blossom. 

456.  Collateral  Chorisis  is  that  in  respect  to 

which  there  is  least  doubt  as  to  the  nature  of  the 

process.     We  have  a  good  example  of  it  in  the 

tetradynamous  stamens  (519)  of  the  Mustard  or 

Cress  family  (Fig.  40G).     Here,  in  a  flower  with 

a  symmetrical  tetramerous  calyx  and  corolla,  we 

have  six  stamens  ;  of  which  the  two  lateral  or 

shorter   ones    are    alternate   with    the    adjacent 

petals,  as  they  normally  should  be,  while  the  four 

are  in  two  pairs,  one  pair  before  each  remaining  interval  of  the 

petals ;  as  is  shown  in  the  annexed  diagram  (Fig.  367).     That  is, 

on  the  anterior  and  on  the  posterior  side  of  the  flower  we  have  two 

stamens  where  there  normally  should  be  but  a  single  one,  and  where, 


FIG.  367.    Diagram  of  a  (tetradynamous)  flower  of  the  order  Cruciferse. 
TIG.  368.    Flower  of  Streptanthus  hyacinthoides,  from  Texas  (the  sepals  and  stamens  re- 
moved), showing  a  forked  or  double  stamen  in  place  of  the  anterior  pair. 


244 


THE   FLOWER. 


indeed,  there  is  but  one  in  a  few  plants  of  this  family.  Now  it  oc- 
casionally happens  that  the  doubling  of  this  stamen  is,  as  it  were, 

arrested  before  com- 
pletion, so  that  in 
place  of  two  stamens 
we  have  a  forked  fila- 
ment bearing  a  pair 
of  anthers ;  as  fre- 
quently happens  in 
some  species  of  Strep- 
tanthus  (Fig.  368). 
Here  the  two  stamens 
in  place  of  one  may 
be  compared  with  a 
compound  leaf  of  two 
leaflets.  In  the  re- 
lated Fumitory  fam- 
ily three  stamens  reg- 
ularly appear  in  the 
place  of  one.  The 
circles  of  the  flower 
are  in  twos  through- 
out ;    viz.    there    is, 

first,  a  pair  of  small  scale-like  sepals ;  alternate  with  these,  a  pair 

of  petals,  which,  in  Dicentra,  &c.  (Fig.  369-371),  are  saccate  or 

spurred  below ;  alternate  and  within  these 

is  a  second  pair  of  petals   (Fig.   372)  ; 

alternate  with  these  are  two  clusters  of 

three  more  or  less  united  stamens,  which 

plainly  occupy  the  place  of  two  single 

stamens.      The  arrangement  of  parts  is 

shown    in   the    annexed   diagram    (Fig. 

373)  ;  where  the  lowest  line  indicates  the 

subtending  bract,  and  therefore  the  anterior  side  of  the  blossom; 

the  two  short  lines  in  the  same  plane  represent  the  sepals  ;  the  two 


FIG.  369.  Dicentra  Cucullaria  (Dutchman's-Breeches),  with  its  kind  of  bulb,  a  leaf,  and  a 
scape  in  flower ;  reduced  in  size.  370.  A  flower  of  the  natural  size.  371.  The  same,  with  the 
parts  separated,  except  the  sepals,  one  of  which  is  seen  at  the  base  of  the  pistil.  372.  The 
inner  pair  of  petals,  with  their  tips  coherent. 

FIG.  373.  Diagram  (cross-section)  of  the  similar  flower  of  Adlumia.  374.  One  of  the  sta- 
mens increased  into  three  by  chorisis  (the  lower  part  of  the  common  filament  is  cut  away). 


CHORISIS    OR   DEDUPLICATION. 


245 


next  within,  the  lateral  and  exterior  petals;  those  alternate  and 
within  these,  the  inner  circle  of  petals ;  and  alternate  with  these  are 
the  anthers  of  the  two  stamen-clusters.  The  centre  is  occupied  by 
a  section  of  the  pistil,  which  consists  of  two  united.  The  three  sta- 
mens are  lightly  connected  in  Dicentra  (Fig.  371)  ;  but  in  Corydalis 
and  Adlumia  there  is  only  one  strap-shaped  filament  on  each  side, 
which  is  three-forked  at  the  tip,  each  fork  bearing  an  anther  (Fig. 
374).  We  have  a  similar  case  in  some  Hypericums  and  in  Elodea 
(Fig.  375),  except  that,  while  the  floral  envelopes  are  in  fives,  the 
circles  within  them  are  commonly  in 
threes.  The  three  members  of  the 
androecium  are  normally  placed,  alter- 
nating with  the  three  members  of  the 
gynreciuni  within,  and  also  with  three 
glands,  which  probably  replace  another 
circle  of  stamens.  Now  each  real 
stamen  is  here  multiplied  into  three, 
united  below  ;  so  that  the  Avhole  compound  body  may  be  viewed  as 
homologous  with  a  compound  trifoliolate  leaf  (289).  If  this  be  so, 
then  each  cluster  of  numerous  stamens  in  the  common  St.  Johns- 
wort  may  be  regarded  as  answering  to  one  stamen  greatly  multiplied 
in  the  same  way,  and  as  analogous  to  a  sessile  decompound  leaf. 
And  the  same  may  be  said  of  each  stamen-cluster  in  the  Linden 
(Fig.  383).  The  actual  development  of  the  cluster,  from  a  protu- 
berance which  in  the  forming  flower-bud  occupies  the  place  of  a 
single  stamen,  has  been  traced  by  Duchatre,  Payer,  &c.  in  this  and 
other  cases. 

457.  Thus  far  we  are  sustained  by  a  clear  analogy  in  the  organs 
of  vegetation.  As  the  leaf  frequently  develops  in  the 
form  of  a  lobed,  divided,  or  compound  leaf,  —  that  is,  as 
a  cluster  of  partially  or  completely  distinct  organs  from 
a  common  base,  —  so  may  the  stamen,  or  even  the  pistil, 
become  compound  as  it  grows,  and  give  rise  to  a  clus- 
ter, instead  of  completing  its  growth  as  a  solitary  organ  : 
and  it  appears  that  the  organogeny  is  strikingly  sim- 
ilar in  the  two  cases.  Nor  is  it  very  unusual  for  petals  to  become 
divided  or  deeply  lobed  in  the  same  manner ;  as,  for  example,  those 


FIG.  375.    Diagram  (cross-section)  of  a  flower  of  Elodea  Virginica.    376.  One  of  the  three 
stamen-clusters,  consisting  of  a  trebled  stamen,  enlarged. 
FIG.  377.     A  petal  of  JMiguonette,  enlarged. 

21* 


246 


THK    FLOWKR. 


of  Mignonette  (Fig.  377).  In  certain  cases  an  analogous  division ' 
takes  place  in  the  opposite  direction,  so  that  the  parts  or  lobes  are 
situated  one  before  the  other.  An  indication  of  this  is  also  mani- 
fest in  the  petals  of  Mignonette,  the  lower  part  or  broad  claw 
of  which  is  slightly  extended  at  its  summit,  on  each  side,  beyond 
the  origin  of  the  many-cleft  limb  or  blade.  Division  in  this  direc- 
tion has  been  termed 

458.  Transverse  or  Vertical  Chorisis.    The  most  familiar  case  is  that 

of  the  croivn,  or  small' and  mostly  two-lobed  ap- 
pendage on  the  inside  of  the  blade  of  the  petals 
of  Silene  (Fig.  378)  and  of  many  other  Caryo- 
phyllaceous  plants.  This  is  more  like  a  case  of 
real  dedoublement  or  unlining,  i.  e.  a  partial  sepa- 
ration of  an  inner  lamella  from  the  outer,  and 
perhaps  may  be  so  viewed.  Stamens  sometimes 
bear  a  similar  and  more  striking  appendage,  as 
in  Larrea,  for  example  (Fig.  379),  and  most 
other  plants'  of  the  Guaiacum  family  ;  also  in  the      378 

Dodder  (Fig.  1044).  Let  it  be  noted  that  in  all  such 
cases  the  appendage  occupies  the  inner  side  of  the  petal 
or  stamen,  and  that  it  is  commonly  two-lobed.  Again, 
before  each  petal  of  Parnassia  (Fig.  381),  although 
slightly  if  at  all  united  with  it,  is  found  a  body  which  in 
P.  palustris  is  somewhat  petal-like,  with  a  considerable 
number  of  lobes,  and  in  P.  Cai'oliniana  is  divided  almost 
to  the  base  into  three  lobes,  which  look  much  like  abortive 
stamens.  The  true  stam- 
ineal  circle,  however,  oc- 
cupies its  proper  place 
within  these  ambiguous 
bodies,  alternate  with  the 
petals.  We  cannot  doubt 
that  the  former  are  of  the 
same  nature  as  the  scale 
of  the  stamens  in  Larrea, 
and  the  crown  of  the  petals 


FIG.  37S-    A  petal  of  Silene  Pennsylvania,  with  its  crown  or  appendage. 

FIG.  379.  A  stamen  of  Larrea  Mexicana,  with  a  scale-like  appendage  cohering  with  its  base 
on  the  inner  side. 

FIG.  380.  Diagram  (cross-section)  of  the  flower  of  Parnassia  Oaroiiniana.  381.  A  petal, 
with  the  appendage  that  stands  before  it. 


CHORISIS    OK    DEDUPLICATION.  247 

of  Silene  ;  and  we  incline  to  consider  the  accessory  body  in  such 
cases  as  homologous  with  the  stipules  of  the  leaf.* 

459.  It  may  also  be  noticed,  that,  while  in  collateral  chorisis  the. 
increased  parts  are  usually  all  of  the  same  nature,  like  so  many 
similar  leaflets  of  a  compound  leaf,  in  what  is  called  transverse  cho- 
risis there  is  seldom  such  a  division  into  homogeneous  parts  ;  but  the 
original  organ  remains,  as  it  were,  intact,  while  it  bears  an  append- 
age of  some  different  appearance  or  function  on  its  inner  face,  or 
at  its  base  on  that  side.     Thus  the   stamens  of  Larrea,  &c.  bear 


*  For  fuller  illustrations  of  these  theoretical  points,  the  student  is  referred  to 
the  figures  and  text  of  The  Genera  of  the  United  States  Flora  Illustrated,  espe- 
cially to  Vol.  2.  —  An  able  writer  in  Hooker's  Journal  of  Botany  and  Kew  Garden 
Miscellany,  Vol.  1,  p.  360,  (with  whom  we  are  in  accord  as  to  the  nature  of  col- 
lateral chorisis,)  "being  totally  at  a  loss  to  find  anything  analogous  in  the 
ordinary  stem-leaves  "  to  this  transverse  or  vertical  multiplication  of  parts,  in- 
clines to  consider  such  appendages  as  those  of  the  petals  of  Silene,  Sapindus, 
Ranunculus,  &c.  as  deformed  glands,  and  the  stamens  thus  situated,  whether 
singly  or  in  clusters,  as  developments  of  new  parts  in  the  axil  of  the  petals,  &c. 
It  appears  to  us,  however,  that  the  leaves  do  furnish  the  proper  analogue  of 
such  appendages  as  those  of  Fig.  378-381,  and  the  similar  petaloid  scales  of 
Sapindaceaj,  Erythroxylea;,  and  the  like,  in  the  ligule  of  Grasses,  and  the  stip- 
ules. The  former  occupies  exactly  the  same  position.  The  latter  form  an 
essential  part  of  the  leaf,  and  usually  develop  in  a  plane  parallel  with  that  of 
the  blade,  but  between  it  and  the  axis  ;  particularly  when  they  are  of  consider- 
able size,  and  serve  as  teguments  of  the  bud,  as,  for  example,  in  Magnolia  (Fig. 
156).  The  combined  intrapctiolar  stipules  of  Melianthus  furnish  a  case  in 
point,  to  be  compared  with  the  two-lobed  internal  scale  of  the  stamens  in  Lar- 
rea, the  two-cleft  adnate  appendage  of  the  petals  in  Caryophyllea^  Sapindus, 
&c. ;  and  instances  of  cleft  or  appendaged  stipules  may  readily  be  adduced  to 
show  that  such  bodies  are  as  prone  to  multiplication  by  division  as  other  foliar 
parts.  The  supposition  of  a  true  axillary  origin  of  the  organs  in  question, 
therefore,  appears  to  be  gratuitous,  and  it  would  certainly  introduce  needless 
complexity  into  the  theory  of  the  flower.  Nor  does  it  throw  any  light  upon 
their  morphology  to  call  such  appendages  of  petals  "  deformed  glands  "  ;  a  term 
which  is  much  too  vague  to  have  any  assignable  morphological  value.  In 
Linum  true  stipules  are  reduced  to  glands.  At  present,  therefore,  we  think  that 
the  same  general  name  may  properly  enough  be  employed  both  for  the  collateral 
and  the  vertical  multiplication  of  organs,  where  two  or  more  bodies  occupy  the 
place  of  one,  carefully  distinguishing,  however,  the  two  different  cases.  Some 
special  term  is  needful  for  discriminating  between  such  multiplication  and  that 
by  the  regular  augmentation  of  floral  organs  through  the  development  of  addi- 
tional circles,  and  none  the  less  so,  because  we  recognize,  in  one  or  both  kinds 
of  chorisis,  modes  of  division  which  are  common  to  the  floral  organs  and  to  the 
foliage. 


248 


THE    FLOWER. 


382 


a  scale-like  appendage ;  the  petals  of  Sapindus,  Cardiospermum, 
&c,  a  petaloid  scale  quite  unlike  the  original  petal ;  the  petals  of 
Parnassia,  a  cluster  of  bodies  resembling  sterile  filaments  united 
below. 

460.  The  Antepositioil  or  superposition  of  parts  which  normally 
alternate  in  the  flower  has  in  some  cases  been  regarded  as  a  case  of 
transverse  chorisis ;  but  it  is  susceptible  of  a  simpler  explanation. 
The  principal  case  that  occurs  is  that  of  the  stamens,  or  the  outer- 
most  circle  of  stamens,  being  placed   directly   before  the   petals 

(in  ordinary  botanical  lan- 
guage opposite  the  petals). 
The  Vine  (Fig.  384-386) 
and  the  Buckthorn  families 
are  good  examples  of  this 
anomaly,  as  also  is  Clay- 
tonia  in  the  Purslane  fam- 
ily. And  in  Linden  and 
many  of  its  allies  a  cluster  of  stamens  (Fig.  382,  383)  stands  be- 
fore each  petal,  the  American  Lindens  384  335 
having  also  a  petal-like  scale  in  the 
centre  of  every  cluster.  The  clusters 
must  be  viewed  as  multiplications  of 
single  stamens  by  collateral  chorisis. 
The  position  of  the  stamens  before 
the  petals  in  these  cases,  as  well  as 
that  of  the  numerous  petals  in  certain 
double  Camellias,  arranged  through- 
out in  five  vertical  ranks,  is  most 
readily  explained  by  supposing  a  re- 
turn to  the  regular  f  or  five-ranked 
phyllotaxis  of  leaves  (240). 

461.  In  the  genuine  Geranium  (Fig.  421)  the  position  of  the  outer 
of  the  two  sets  of  stamens  before  the  petals  evidently  results 
from  the  abortion  of  an  exterior  circle  (486)  ;  and  perhaps  this  is 
the  case  in  the  Primrose  family  also.  In  the  Barberry  family  there 
is  an  apparent  anteposition  of  the  sepals,  petals,  and  stamens  through- 

FIG.  382.  Diagram  of  the  flower  of  the  American  Linden,  in  a  cross-section  of  the  bud. 
383.  A  cluster  of  stamens  with  the  petal-like  body  in  the  middle. 

FIG.  3S4.  Flower  of  the  Grape,  casting  its  petals  before  expansion.  385.  The  same,  with- 
out the  petals  :  both  show  the  glands  distinctly,  within  the  stamens.  3S6.  Diagram  of  the 
flower. 


COALESCENCE    OF    ITS    PARTS.  249 

out.  But  this  arises  from  the  symmetrical  augmentation  of  each  set 
of  organs  into  two  circles,  which  in  the  expanded  flower  appear  like 
one.  In  the  flower-bud  of  the  Barberry  the  calyx  is  seen  to  consist 
of  two  alternating  circles  of  sepals,  three  in  each  ;  the  corolla,  of  two 
circles  of  petals,  three  in  each  ;  the  three  exterior  petals  alternating 
as  they  should  with  the  inner  circle  of  sepals,  and  the  three  interior 
ones  alternating  with  these.  But  when  the  flower  opens,  the  six 
petals,  spreading  apparently  as  one  whorl,  are  necessarily  opposed 
to  the  six  sepals  ;  and  the  six  stamens  in  two  circles,  which  are  still 
more  confluent  into  one  whorl,  are  equally  opposed  to  these,  taken  six 
and  six  ;  although  they  really  alternate  in  circles  of  three.  In  other 
words,  decussating  verticils  of  threes  necessarily  form  six  vertical 
ranks  (251,  441).  It  is  just  the  same  in  the  Lily,  Crocus,  and  most 
Monocotyledonous  plants ;  where  the  perianth  is  composed  of  six 
similar  leaves  in  two  circles,  and  the  andrcecium  of  six  stamens  in 
two  circles,  giving  a  regular  alternation  in  threes  ;  although,  when 
taken  by  the  casual  observer  as  composed  of  two  circles  of  six,  it 
gives  the  appearance  of  six  stamens  before  as  many  petals. 

462.  The  Coalescence  or  union  of  the  parts  of  the  same  whorl  or 
set  of  organs  is  so  frequent,  that  few  cases  are  to  be  found  in  which 
it  does  not  occur,  to  a  greater  or  less  extent,  in  some  portion  of  the 
flower.  When  the  sepals  are  thus  united  into  a  cup  or  tube,  the 
calyx  is  said  to  be  monosepalous,  or,  more  correctly,  gamosepalous  ; 
when  the  petals  are  united,  the  corolla  is  said  to  be  monopetcdous,  or 
gamopetalous.  The  latter  is  the  appropriate  term,  as  it  denotes 
that  the  petals  are  combined  ;  but  the  former  is  in  common  use,  al- 
though etymologically  incorrect,  as  implying  that  the  corolla  consists 
of  a  single  petal.  The  current  names,  in  these  cases,  were  given 
long  before  the  structure  was  rightly  understood.  So,  also,  such  a 
calyx  or  corolla  is  said  to  be  entire,  when  the  sepals  or  petals  are 
united  to  their  very  summits  ;  or  to  be  toothed,  lobed,  cleft,  or  parted, 
according  to  the  degree  in  which  the  union  is  incomplete  ;  this  lan- 
guage being  employed  just  as  in  the  case  of  the  division  of  leaves 
(281).  On  the  other  hand,  when  the  sepals  are  not  united,  the  calyx 
is  said  to  be  polysepalous  ;  and  when  the  petals  are  distinct,  the 
corolla  is  said  to  be  polypetalous ;  that  is,  composed  of  several 
petals. 

463.  The  union  of  the  stamens  with  each  other  may  occur  either 
by  their  filaments,  as  in  the  Pea  and  most  of  the  Pulse  family,  or  by 
their  anthers,  as  in  the  Sunflower  and  the  whole  Composite  family,  or 


250 


THE    FLOWER. 


by  both  the  filaments  and  the  anthers,  as  in  Lobelia  and  the  Gourd. 
An  account  of  the  modes  of  such  union,  and  of  the  terms  employed 
to  express  them,  may  be  found  in  Section  VI.  The  union  of  the 
pistils  is  still  more  common  than  that  of  stamens,  and  is  illustrated  in 
Section  VII. 

464.  The  terms  union,  cohesion,  and  the  like,  must  not  be  under- 
stood to  imply  that  the  organs  in  question  were  first  formed  as 
distinct  parts,  and  subsequently  cohei-ed.  This  is  seldom  the  case. 
The  union  is  congenital ;  the  members  of  a  gamosepalous  calyx,  a 
gamopetalous  corolla,  &c.  showed  their  union  from  the  earliest 
period.  The  language  we  use  has  reference  to  our  idea  of  these 
parts,  as  answering  each  to  a  single  leaf.  We  might  more  cor- 
rectly say  that  the  several  leaves  of  the  same  circle  have  failed  to 
isolate  themselves  as  they  grew.  The  same  remark  applies  to  the 
analogous  case  of 

4G5.  Adliatioil,  or  Consolidation,  the  union  of  different  circles  of 
floral  organs  with  one  another.  This  may  take  place  in  various  de- 
grees. It  presents  the  appearance  of  one  circle  or  set  of  parts  grow- 
ing out  of  another,  as  the  corolla  out  of  the  calyx,  the  stamens  out  of 
the  corolla,  or  all  of  them  out  of  the  pistil ;  and  therefore  disguises 
the  real  origin  of  the  floral  organs  from  the  receptacle  or  axis,  in 
successive  series,  one  within  or  above  the  other  (421).  The  con- 
sideration of  the  flower  as  respects  such  consolidation,  or  its  ab- 
sence, gives  rise  to  three  terms  which  are  much  used  in  descrip- 
tive botany,  and  which  the  student  should  thoroughly  understand, 
viz.  hypogynous,  perigynous,  and  epigynous. 

466.  The  first  of  these 
terms  applies  to  the  case  in 
which  there  is  no  adnation  or 
consolidation  of  unlike  parts. 
That  is,  when  the  calyx, 
corolla,  and  stamens  are 
borne  (i.  e.  inserted)  on  the 
receptacle,  they  are  said  to 
be  hypogynous  (from  two 
Greek  words  meaning  under 
the  pistil),  as  in  Buttercup,  Flax  (Fig.  387),  &c.  The  floral  organs 
in  such  cases  are  also  said  to  he  free  ;  which  is  the  term  opposed  to 

FIG.  387.  Vertical  section  of  a  flower  of  the  Common  Flax,  showing  the  normal  or  hypo- 
gynous insertion  of  parts. 


CONSOLIDATION    OR    ADNATION. 


251 


the  adhesion  of  one  organ  to  another,  as  that  of  distinct  is  to  the 
cohesion  of  the  parts  of  the  same  whorl  or  set  of  organs.  Thus,  the 
stamens  are  said  to  be  distinct,  when  not  united  with  each  other,  and 
to  be  free,  when  they  contract  no  adhesion  to  the  petals,  sepals,  or 
pistils ;  and  the  same  language  is  equally  applied  to  all  the  floral 
organs.  The  word  connate  (born  united)  is  applied  either  to  the 
congenital  union  of  homogeneous  parts  (as  when  we  say  that  the  two 
leaves  of  the  upper  pairs  of  the  Honeysuckle  are  connate,  Fi"-.  294, 
the  sepals  or  stamens  are  connate  into  a  tube,  or  the  pistils  into  a 
compound  pistil),  or  to  the  coalescence  of  heterogeneous  parts  (as 
that  of  the  petals  with  the  calyx,  or  of  both  with  the  pistil).  But 
the  word  adnate  belongs  to  the  latter  case  only. 

467.  When  such  consolidation  takes  place,  and  the  petals  and 
stamens  (which  almost  always  accompany  each  other),  or  either  of 
them,  are  inserted  on  the 
calyx,  i.  e.  are  adnate  with 
the  base  of  the  calyx  (as  in 
the  Cherry,  Fig.  388,  or 
Purslane,  Fig.  389),  they  are 
said  to  be  perigynous  (liter- 
ally, placed  around  the  pis- 
til). The  real  origin  of  the 
parts  must  be  the  same  as  in 
the  former  case,  that  is,  the 
parts  really  belong  to  the  re- 
ceptacle, in  successive  circles, 
one  above  or  within  the  other, 
first  the  sepals,  then  the  pet- 
als, within  these  the  stamens, 
and  within  or  above  these 
the  pistils  ;  but  the  true  origin 
or  position  of  some  of  the  parts  is  here  obscured  by  the  adnation,  at 
their  base  at  least,  of  parts  which  are  normally  separate.  In  Fig. 
388,  the  petals  and  stamens  are  adnate  to  the  lower  part  of  the 
calyx,  but  all  are  free  from  the  pistil.  But  in  Fig.  389,  all  four 
organs  are  consolidated  below,  as  far  as  to  the  middle  of  the 
ovary. 

FIG.  3S3.  Vertical  section  of  a  flower  of  the  Cherry,  to  show  the  perigynous  insertion  of 
the  petals  and  stamens. 

FIG  3S9.  Similar  section  of  the  flower  of  the  Purslane,  showing  an  adnation  of  parts  with 
the  lower  part  of  the  overy. 


252 


THE    FLOWER. 


468.  In  the  Apple,  Hawthorn  (Fig.  390),  and  many  other  plants, 
the  consolidation  extends  farther,  and  the  calyx  is  adnate  to,  i.  e. 

.  invests  and  coheres  with  the 
whole  surface  of  the  ovary, 
which  accordingly  appears 
to  be  under  the  rest  of  the 
flower,  instead  of  the  upper- 
most and  innermost  part,  as 
it  properly  is.  The  earlier 
botanists  called  the  flower, 
or  calyx,  in  such  cases,  supe- 
rior, and  the  ovary  and  fruit 
inferior ;  and  when  no  such  consolidation  occurs,  the  flower,  or 
calyx,  &c.  was  said  to  be  inferior,  and  the  ovary  superior.  But 
these  terms  should  be  superseded  by  the  equivalent  and  much  more 
appropriate  expressions  of  calyx  adherent,  in  the  one  case,  and  calyx 
free,  in  the  other  ;  or  by  that  of  ovary  coherent  with  the  calyx,  and 
ovary  free  from  the  ccdyx,  which  is  the  same  thing  in  other  words.* 
More  commonly  the  corolla  and  the  stamens  are  adnate  to  the 
calyx  beyond  where  these  parts  all  separate  from  the  pistil ;  in  which 
case  they  are  still  perigynous,  or  borne  on  the  calyx.  In  some 
such  cases,  as  in  the  Evening  Primrose  and  Fuchsia,  the  tube  of 
the  calyx  is  prolonged  far  beyond  the  ovary,  and  the  petals  and 
stamens  are  inserted  on  it  just  below  where  it  separates  into  its 
distinct  lobes. 

469.  In  other  flowers  the  petals  and  the  stamens  are  distinct  at 
the  line  where  the  calyx  separates  from  the  top  of  the  ovary,  or  are 
borne  on  the  edge  or  face  of  a  thickened  disc  (489)  which  crowns  its 
summit,  as  in  Aralia  (Fig.  410),  the  Ivy,  and  all  that  family,  in  the 
whole  Parsley  family,  the  Cornel  family,  the  Cranberry  (Fig.  391), 
and  the  like.  The  stamens,  &c,  being  then  apparently  borne  on  the 
ovary,  are  said  to  be  epigynous  (from  two  Greek  words  meaning 
"  on  the  pistil "). 


*  A  favorite  view  at  present  is  that  the  calyx  in  many  eases  (as  in  the  Rose, 
Apple,  &c.)  actually  begins  at  the  place  where  it  is  distinct  from  the  parts  with- 
in, and  that  the  so-called  tube  is  the  summit  of  the  peduncle  hollowed  out,  or 
developed  around  the  pistils.  This  view  can  be  correct  in  certain  cases  only, 
and  the  difference  between  it  and  the  current  view  is  really  not  so  great  as  it 
seems. 


FIG.  390.    Flower  of  Hawthorn  vertically  divided,  to  show  the  calyx  adnate  to  the  ovary. 


ITS    IRREGULARITY. 


253 


470.  In  some  few  plants  the  stamens  continue  this  adnation  a  little 
further,  and  cohere  with  the  style,  either  with  its  base  only,  as  in 
some  species  of  Asarum,  or  with  its 

whole  length,  as  in  Cypripedium  fj 

(Fig.  468)  and  the  whole  Orchis  | 

family.     Then  the  flower  is  said  \\  i\i|    j  \\ 

to  be  gynandrous  ;  —  from  two 
Greek  words  equivalent  in  mean- 
ing to  stamens  and  pistil  com- 
bined (519). 

471.  Irregularity.    The  flower 

is  irregular  when  the  parts  of  its 

different    circles,   or   of   one    or  391 

more  of  them,  are  not  all  alike  in  number, 
shape,  or  size.  Irregularity  may  be  the  re- 
sult, therefore,  either  of  the  abortion  or  dis- 
appearance of  some  parts,  or  of  their  un- 
equal development  or  unequal  union.  The 
latter  case  may  be  first  considered. 

472.  The  Pea  tribe  affords  a  familiar 
illustration  of  irregular  flowers  arising  from 
the  unequal  size  and  dissimilar 
form  of  the  floral  envelopes ; 
especially  of  the  corolla,  which, 
from  a  fancied  resemblance  to  a 
butterfly  in  the  flower  of  the 
Pea,  Locust  (Fig.  392),  &c,  has 
been  called  papilionaceous.  The 
petals  of  such  a  corolla  are  dis- 
tinguished by  separate  names ; 
6  the  upper  one,  which  is  usually 
most  conspicuous,  being  termed 
the  vexillum,  standard,  or  banner 
(Fig.  392',  a) ;  the  two  lateral 
3^(  (b)  are  called  tvings  {alee),  and 

the   two   lower    (c),  which   are 
usually  somewhat  united  along  their  anterior  edges,  and  together 

FIG.  391.  Flower  of  Cranberry  divided  lengthwise,  showing  the  petals  and  stamens  epi- 
gynous. 

FIG.  392.  Front  view  of  a  flower  of  the  common  Locust-tree  (Hobinia  Pseudacacia). 

FIG.  392'.  Corolla  of  the  same,  the  petals  displayed. 

22 


254 


THE    FLOWER. 


form  a  body  in  shape  resembling  the  keel,  or  rather  the  narrow 
prow,  of  an  ancient  vessel,  are  named  the  carina  or  heel.  The  calyx 
of  the  same  blossom  is  slightly  irregular  by  the  unequal  union  of 
parts,  the  two  upper  sepals  being  united  higher  than  the  other  three. 
In  Baptisia  these  two  sepals  are  coalescent  to  the  tip,  or  nearly  so, 

causing  the  calyx  to  ap- 
pear as  if  formed  of  four 
sepals  instead  of  five  In 
most  Lupines,  not  only  are 
the  two  upper  sepals  coa- 
lescent into  one  body  near- 
ly or  quite  to  the  tip,  but 
the  three  remaining  ones 
are  likewise  united  into 
one  body,  on  the  lower  side 
of  the  flower,  thus  giving 
the  calyx  the  appeai-ance 
of  consisting  of  two  petals 
in  place  of  five.  The  ir- 
regularity of  papilionaceous  flowers  likewise  affects  the  stamens, 
which,  although  of  symmetrical  number,  396 

viz.  ten,  or  two  circles,  are  in  most  cases 
unequally  coalescent,  nine  of  them  being 
united  by  the  cohesion  of  their  filaments 
for  the  greater  part  of  their  length, 
while  the  tenth  (the  posterior)  stamen 
is  distinct ;  as  is  illustrated  in  the  sec- 
tion on  the  stamens  (518).  But  in 
Amorpha  (Fig.  395),  which  belongs  to 
the  same  tribe  of  plants,  the  ten  stamens 
are  united  barely  at  their  base ;  and 
there  is  a  complete  return  to  regularity 
in  those  of  Baptisia  (Fig.  394)  and 
Sophora,  which  are  perfectly  distinct  or 
separate.  The  Violet  (Fig.  397)  offers 
another  very  familiar  form  of  irregu- 
lar flowers  ;   the  irregularity  belonging 

FIG.  393.  Papilionaceous  flower  of  Baptisia.  394.  The  same,  with  the  petals  removed, 
showing  the  ten  distinct  stamens. 

FIG.  395.  Flower  of  Amorpha.  395'.  The  same,  with  the  solitary  petal  removed,  showing 
the  slightly  monadelphous  stamens. 

FIG.  396.     Flower  of  Viola  sagittata.    397.  Its  sepals  and  petals  displayed. 


SUPPRESSION    OR    ABORTION    OF    TARTS.  255 

mainly  to  the  corolla,  the  lower  petal  of  which  is  prolonged  back- 
ward into  a  sac  or  spur.  The  Larkspur  and  Monkshood  (Fig.  398- 
402)  are  irregular  both  in  the  calyx  and  the  corolla,  not  only  by  a 
diversity  in  the  size  and  shape  of  homologous  parts,  but  also  by  the 
suppression  of  some  of  them.  "We  may  therefore  consider  them 
under  the  next  head. 

•473.  Of  irregular  monopetalous  flowers  the  most  common  form  is 
the  bilabiate  or  two-lipped,  as  in  the  corolla  of  the  Sage,  Snap- 
dragon, and  most  of  the  large  families  to  which  they  belong  (Fig. 
4G0)  :  this,  like  the  calyx  of  the  Lupine,  described  above,  arises 
from  the  unequal  union  of  the  parts.  The  same  is  the  case  with 
the  two-lipped  corolla  of  the  "Woodbine  and  other  Honeysuckles, 
only  here,  instead  of  two  lobes  or  petals  forming  the  upper  lip  and 
three  the  lower,  four  petals  enter  into  the  composition  of  the  upper 
lip,  leaving  only  one  for  the  lower  (Fig.  861).  The  Trumpet 
Honeysuckle  returns  nearly  to  regularity  again,  the  whole  five 
petals  being  coalescent  into  a  tube  to  near  the  top,  leaving  an  al- 
most equally  five-lobed  border.  The  corollas  of  Germander  (Fig. 
99 G)  and  of  Lobelia  (Fig.  902)  are  further  irregular  by  a  want  of 
union  on  the  upper  side  of  the  blossom :  and  the  ligulate  or  open 
and  strap-shaped  corolla  of  Coreopsis  (Fig.  325,  c)  and  other  Com- 
posite evidently  answers  to  such  a  regular  monopetalous  corolla  as 
a,  split  down  on  one  side  and  outspread. 

474.  Suppression  or  Abortion,  that  is,  the  complete  or  the  partial 
obliteration  of  some  member,  is  a  common  cause  of  irregularity. 
The  term  suppressio?i  is  used  when  parts  which  belong  to  the  plan 
of  the  blossom  do  not  actually  appear  in  it.  The  term  abortion  is 
applied  not  only  to  such  disappearance,  but  to  partial  obliteration, 
as  where  a  stamen  is  reduced  to  a  naked  filament,  or  to  a  mere  rudi- 
ment or  vestige,  answering  to  a  stamen  and  occupying  the  place 
of  one,  but  incapable  of  performing  its  office.  Such  obliteration, 
whether  partial  or  complete,  may  affect  either  a  whole  circle  of 
organs  or  merely  some  of  its  members.  The  former  interferes  with 
the  completeness  of  a  flower,  and  may  obscure  the  normal  order  of 
its  parts.  The  latter  directly  interferes  with  the  symmetry  of  the 
blossom,  and  may  be  first  considered. 

475.  Suppression  of  some  Parts  of  a  Circle  of  Organs.    The  Larkspur 

and  Aconite  or  Monkshood  furnish  good  examples  of  flowers  which 
are  both  irregular  and  symmetrical.  The  calyx  of  the  Larkspur 
(Fig.  398,  399)  is  irregular  by  reason  of  the  dissimilarity  of  the  five 


256 


THE    FLOWER. 


sepals,  one  of  which,  the  uppermost  and  largest,  is  prolonged  poste- 
riorly into  a  long  and  hollow  spur.     Within  these,  and  alternate  with 


them  as  far  as  they  go,  are  the  petals,  only  four  in  number,  and  these 
of  two  shapes,  the  two  upper  ones  having  long  spurs  which  are  re- 

FIG.  398.  Flower  of  a  Larkspur.  399.  The  five  sepals  (outer  circle)  and  the  four  petals 
(inner  circle)  displayed.    400.  Ground-plan  of  the  calyx  and  corolla. 

FIG.  401.  Flower  of  an  Aconite  or  Monkshood  402.  The  five  sepals  and  the  two  small 
and  curiously-shaped  petals  displayed  :  also  the  stamens  and  pistils  in  the  centre.  403. 
Ground-plan  of  the  calyx  and  corolla ;  the  dotted  lines,  as  in  Fig.  400,  representing  the  sup- 
pressed parts. 


SUPPRESSION    OR   ABORTION    OF   PARTS. 


257 


ceivecl  into  the  spur  of  the  upper  sepal ;  the  two  lateral  ones  having 
a  small  but  broad  blade  raised  on  a  stalk-like  claw  ;  and  the  place 
which  the  fifth  and  lower  petal  should  occupy  (marked  in  the  ground 
plan,  Fig.  400,  by  a  short  clotted  line)  is  vacant,  this  petal  being  sup- 
pressed, thereby  rendering  the  blossom  unsymmetrical.  In  Aconite, 
(Fig.  401,  402)  the  plan  of  the  blossom  is  the  same,  but  the  upper- 
most and  largest  of  the  five  dissimilar  sepals  forms  a  helmet-shaped  or 
hood-like  body ;  and  as  to  the  petals,  three  are  wanting  altogether 
(their  places  are  shown  by  the  dotted  lines  in  the  ground  plan,  Fig. 
403)  ;  the  two  upper  ones,  which  extend  under  the  hood,  only  re- 
main, and  these  are  so  reduced  in  size  and  so  anomalous 
in  shape  that  they  would  not  ordinarily  be  recognized  as 
petals.  One  of  them  enlarged  is  exhibited  in  Fig.  404. 
Petals,  &c.  of  this  and  other  extraordinary  forms  were 
termed  by  Linnaeus  Nectaries,  an  unmeaning  or  mislead- 
ing name,  as  they  are  no  more  likely  to  secrete  honey 
than  ordinary  petals  are. 

405  476.  The  papilionaceous  corolla  (472) 

becomes  strikingly  unsymmetrical  by 
suppression  in  Amorpha  (Fig.  395). 
Here  the  corolla  is  uniformly  reduced  to 
a  solitary  petal  (the  standard),  the  other 
four  petals  being  totally  obliterated. 
This  obliteration  is  foreshadowed  in  Ery- 
thrina  herbacea  of  the  Southern  States,  and  other 
species,  in  which  all  the  petals  except  the  standard 
are  small  and  inconspicuous.  While  the  blossom 
of  the  common  Iiorsechestnut,  although  irregular, 
is  symmetrical,  so  far  as  respects  the  calyx  and 
corolla,  that  of  our  nearly  related  Buckeyes  gener- 
ally wants  one  of  the  five  petals,  a  vacant  place  on 
the  anterior  side  of  the  flower  indicating  its  absence. 
477.  The  suppression  or  abortion  of  eome  of  the 
stamens  requisite  to  the  symmetry  of  the  blossom  is 
According  to  the  ordinary  view,  the  six  stamens  of 
the  flowers  of  the  Mustard  family  (Fig.  405,  406),  where  the  sepals 
and  petals  are  in  fours,  is  explained  by  supposing  that,  out  of  two 
circles  of  stamens,  four  in  each,  two  stamens  of  the  outer  circle  are 


very  common. 


FIG.  404.     One  of  the  petals  of  an  Aconite  or  Monkshood,  enlarged. 
FIG.  405.  Flower  of  Mustard     406.  Its  six  stamens  and  the  pistil,  enlarged. 
22* 


258 


THE    FLOWER. 


suppressed.  But  we  incline  to  the  opinion  that  this  sort  of  flower 
is  rendered  unsymmetrical,  not  by  the  suppression  of  two  short  sta- 
mens, but  by  the  chorisis  or  division  of  the  two  stamens  each  into  a 
pair  (456,  Fig.  368). 

478.  Most  flowers  which  are  irregular  by  the  unequal  union  of 
407  the  petals,  especially  those  with  a  bi- 

labiate corolla  (473,  511),  are  likewise 
unsymmetrical  by  the  abortion  of  one 
or  more  of  the  stamens.  In  the  Cat- 
nip, Balm,  &c,  and  in  the  Snapdragon, 
Monkey-flower,  Foxglove,  and  the 
like,  as  also  in  Gerardia  (Fig.  407), 
where  the  corolla  is  only  slightly  ir- 
regular, four  stamens  occupy  their 
proper  places  alternate  with  its  lobes, 
but  the  fifth  stamen  is  altogether  want- 
ing. In  its  place,  however,  the  corolla 
of  the  Figwort,  belonging  to  the  same 
family  as  the  Snapdragon  and  Ge- 
rardia, bears  a  small  scale,  and  that  of 
Chelone  and  Pentstemon  (Fig.  408) 
bears  an  antherless  filament,  which, 
from  its  position,  must  be  the  wanting 
stamen,  in  an  abortive  state  ;  and  in 
one  species  it  has  actually  been  found 
with  a  perfect  or  an  imperfect  anther, 
completing  the  symmetry  of  the  flow- 
er. The  four  perfect  stamens  in  these 
cases  are  of  unequal  length,  two  of 
them  being  longer  than  the  other  two 
(i.  e.  they  are  didynamous,  520). 
The  two  shorter  stamens  also  disappear  in  many  such  plants,  as  in 
Gratiola  or  Hedge-Hyssop,  —  sometimes  leaving  vestiges  in  their 
place,  and  sometimes  not ;  also  in  Sage,  Horse-Mint,  and  the  like. 
Here  three  stamens  out  of  five  are  suppressed.     So  they  commonly 


FIG.  407.  Corolla  of  Gerardia  purpurea  laid  open,  with  the  four  stamens  the  place  which 
the  fifth  should  occupy  indicated  by  a  cross. 

FIG.  408.  Corolla  of  Pentstemon  grandiflorus  laid  open,  with  its  four  stamens,  and  a  sterile 
filament  in  the  place  of  the  fifth  stamen. 

FIG.  409.  Corolla  of  Catalpa  laid  open,  with  two  perfect  stamens  and  the  vestiges  of  three 
abortive  ones. 


SUPPRESSION    OR   ABORTION    OF    PARTS.  259 

are  in  the  blossom  of  Catalpa  (Fig.  409),  but  their  vestiges  remain 
in  the  form  of  small  sterile  filaments,  two  o£, /which,  however,  occa- 
sionally bear  anthers,  either  perfect  or  rudiniefrtary. 

479.  The  suppression  of  a  portion  of  the  pistils  required  to  com- 
plete the  symmetry  of  the  flower  is  exceedingly  common.  The 
tendency  to  obliteration  seems  to  increase  as  we  advance  towards 
the  centre  of  the  blossom,  owing,  doubtless,  to  the  greater  pressure 
exerted  on  the  central  parts  of  the  bud,  and  the  progressively  di- 
minished space  the  organs  have  to  occupy  on  the  conical  receptacle. 
Thus,  while  the  corolla,  when  present  at  all,  almost  always  consists 
of  as  many  leaves  as  the  calyx,  the  members  of  the  stamineal  circle 
or  circles  are  frequently  fewer  in  number,  and  the  pistils  are  still 
more  commonly  fewer,  excepting  where  the  axis  is  prolonged  for 
the  reception  of  numerous  spiral  cycles.  Thus,  the  pistils,  which 
present  the  symmetrical  number  in  Sedum,  and  all  plants  of  that 
family  (Fig.  334,  335,  355,  3G1),  are  reduced  to  two,  or  rarely  three, 
in  the  allied  Saxifrage  family,  while  the  other  floral  circles  are  in 
fives.  So,  in  the  Wild  Sarsaparilla  (Fig.  410)  and  Spikenard,  the 
flowers  are  pentamerous  throughout,  although  the  ovaries  of  the  five 
pistils  are  united  into  one ;  but  they  are  reduced  to  three  in  the 
Ground-nut,  and  to  two  in  the  Ginseng,  belonging  to  the  same  genus, 
as  also  in  all  Umbelliferous  plants.  Although  the  pistils  are  in- 
definitely augmented  in  the  Rose,  Strawberry,  and  the  greater  part 
of  Rosaceous  plants,  or  are  of  the  normal  number  five  in  Spiraea, 
yet  there  are  only  two  in  Agrimonia,  one  or  rarely  two  in  Sangui- 
sorba,  and  uniformly  one  in  the  Plum  and  Cherry  (Fig.  388), 
although  the  flowers  of  the  whole  order  are  formed  on  the  pentame- 
rous, or  sometimes  the  tetramerous  plan,  and  with  a  strong  tendency 
to  augmentation  of  all  the  organs.  And  the  Pulse  family  has,  almost 
without  exception,  five  members  in  its  floral  envelopes,  and  ten,  or 
two  circles,  in  its  stamens,  but  only  a  single  pistil  (Fig.  358). 

480.  Suppression  of  one  or  more  whole  Circles.    A  complete  flower, 

as  already  remarked  (41 G),  comprises  four  whorls  or  sets  of  organs; 
namely,  calyx,  corolla,  stamens,  and  pistils.  When  any  of  these  four 
circles  or  kinds  of  organs  are  wanting,  the  flower  is  said  to  be  in- 
complete. The  non-production  of  any  one  or  more  of  the  whorls  is 
not  uncommon.  The  calyx,  however,  is  seldom  if  ever  wanting 
when  the  corolla  is  present,  or  rather,  when  the  floral  envelopes  con- 
sist of  only  one  whorl  of  leaves,  they  are  called  calyx,  whatever  be 
their  appearance,  texture,  or  color,  unless  it  can  somehow  be  shown 


260 


THE    FLOWER. 


that  an  outer  circle  is  suppressed.*  For  since  the  calyx  is  fre- 
quently delicate  and  petal-like  (in  botanical  language  petahid  or 
colored),  and  the  corolla  sometimes  greenish 
or  leaf-like,  the  only  real  difference  between 
the  two  is,  that  the  calyx  represents  the 
outer,  and  the  corolla  the  inner  series ;  and 
even  this  distinction  becomes  more  or  less 
arbitrary  when  either,  or  both,  of  these  or- 
gans consist  of  more  than  one  circle.  The 
apparent  obliteration  of  the  calyx  in  some 
cases  is  owing  to  the  entire  cohesion  of  the 
tube  with  the  ovary,  and  the  reduction  of  the  free  portion,  or  limb, 
to  an  obscure  ring  or  border,  either  slightly  toothed  or  entire,  as  in 
Aralia  (Fig.  410),  Fedia  (Fig.  882),  Cornus,  the  fertile  flowers  of 
Nyssa,  &c.  In  Composite,  the  partially  obliterated  limb  of  the 
calyx,  when  present  at  all,  consists  of  scales,  teeth,  bristles,  or  a 
ring  of  slender  hairs  (as  in  the  Thistle),  and  receives  the  name  of 
pappus. 

481.  The  petals,  however,  are  frequently  absent;  when  the  flower 
is  said  to  be  apetalous,  as  in  the  Anemone  (Fig.  411),  Clematis, 
Caltha,  &c,  in  the  Crowfoot  family, 
other  genera  of  which  are  furnished 
with  both  calyx  and  corolla ;  and  as 
in  some  species  of  Buckthorn,  while 
others  have  manifest  although  small 
petals.  They  are  constantly  wanting 
in  a  large  number  of  families  of  Ex- 
ogenous plants,  which  on  this  account 
form  the  division  Apetalcs.  When 
the  calyx  is  present  while  the  corolla 
is  wanting,  the  flower  is    said  to  be 

monochlamydeous,  that  is,  with  a  perianth  (417)  or  floral  envelope  of 
only  one  kind ;  as  in  the  cases  above  mentioned. 


*  In  our  Northern  Zanthoxylum  the  monochlamydeous  perianth  which  is 
present  may,  however,  be  justly  held  to  be  the  corolla,  and  not  the  calyx,  be- 
cause the  five  stamens  alternate  with  it,  just  as  they  do  with  the  undoubted 
petals  of  Z.  Carolinianum  :  in  this  case,  therefore,  we  may  say  that  the  calyx, 
and  not  the  corolla,  is  suppressed.    See  Genera  Illustrate!,  Vol.  2,  p.  148,  tab.  156. 


FIG.  410.    Flower  of  Aralia  nudicaulis,  vertically  divided  ;  the  limb  of  the  calyx  obsolete. 
FIG.  411.    Flower  of  Anemone  Pennsylvania ;  apetalous,  the  calyx  petaloid. 


SUPPRESSION    OR   ABORTION    OF    PARTS. 


261 


482.  In  some  flowers,  moreover,  as  in  the  Lizard's-tail  (Fig.  412), 
both  the  calyx  and  the  corolla  are  entirely  wanting,  and  the  blossom 
is  achlamydeous,  i.  e.  destitute  of  any  perianth 
or  floral  envelopes  whatever.  Having  the  es- 
sential organs,  viz.  the  stamens  and  pistils,  how- 
ever, this  flower  also  is  perfect  {hermaphrodite, 
or  bisexual),  although  incomplete. 

483.  The  abortion  of  all 
the  stamens  or  all  the  pis- 
tils of  a  flower  is  common 
enough,  as  well  in  flowers  that  have  as  in 
those  that  have  not  complete  floral  envelopes ; 
but  whenever  either  of  these  essential  organs 
are  abortive  or  wanting  in  some  blossoms,  they 
are  present  in  others  of  the  same  species, 
either  on  the  same  or  on  different  individuals. 
Flowers  of  this  kind  having  stamens  only  or 
pistils  only  are  said  to  be  separated,  diclinous, 
or  unisexual.  And  the  flower  which  has  the 
stamens  but  no  pistils,  or  only  imperfect  ones,  is  said  to  be  staminate, 
sterile,  or  male  ;  while 
that  provided  with 
pistils,  but  with  no 
stamens,  or  only  im- 
perfect ones,  is  pis- 
tillate, fertile,  or  fe- 
male. Not  to  multi- 
ply examples,  in  Smi- 
lax  and  in  Menisper- 
mum  (Fig.  413,  414) 
we  have  good  instan- 
ces of  separated  flow- 
ers in  which  the  abor- 
tion is  confined  to  the 
stamens  or  the  pistils, 
the  floral  envelopes 
being     present     and  418  417 

FIG.  412.     Flower  of  Lizard's-tail  (Saururus  ceriums),  magnified. 

FIG.  413.  A  staminate  flower  of  Menispermum  or  Moonseed.  414.  A  pistillate  flower  of 
the  same.     The  latter  has  six  abortive  stamens  :  the  former,  mere  vestiges  of  pistils. 

FIG  415.  A  catkin  of  staminate  flowers  of  Salix  alba.  416.  A  single  staminate  flower  de- 
tached and  enlarged  (the  bract  turned  from  the  eye).  417.  A  pistillate  catkin  of  the  same 
species.    41S   A  detached  pistillate  flower,  magnified. 


262  THE    FLOWER. 

complete.  And  in  the  "Willow  (Fig.  415-418)  we  have  separated 
flowers  extremely  simplified  by  abortion.  The  flowers  are  crowded  in 
catkins,  each  one  in  the  axil  of  a  bract :  the  staminate  flowers  consist 
of  a  few  stamens  merely,  in  this  species  of  only  two  (Fig-  41 G),  and  the 
pistillate,  of  a  pistil  merely  (Fig.  418).  That  is,  the  flowers  are  wholly 
destitute  of  calyx  and  corolla  (unless  a  little  glandular  scale  on  the 
upper  side  should  be  a  rudimentary  perianth  of  a  single  piece),  and 
in  one  set  of  blossoms  the  stamens  are  also  suppressed ;  in  another, 
the  pistils.  The  stamens  vary  in  number  in  different  species,  from 
two  to  five.  If  there  were  only  one  of  the  latter,  an  instance  would 
be  afforded  of  flowers  reduced,  not  merely  to  one  kind  of  organ,  but  to 
a  single  member.  Now  there  is  one  species  of  Willow,  which  ap- 
pears to  have  its  sterile  blossoms  reduced  to  a  solitary  stamen.  It 
has  therefore  been  named  Salix  monandra.  But  on  in- 
spection this  seemingly  single  stamen  is  found  to  consist 
of  two  united  with  each  other  quite  to  the  top  (Fig. 
419).  Here,  as  in  many  other  cases,  the  normal  condi- 
tion of  the  flower  is  not  only  much  altered  by  the  sup- 
pression of  most  of  the  organs,  but  disguised  by  the  coa- 
lescence of  those  that  remain. 

484.  In  separated  flowers  the  two  kinds  of  blossoms 
may  be  borne  either  upon  different  parts  of  the  same 
individual,  or  upon  entirely  different  individuals.  The  flowers  are 
said  to  be  monoecious  when  both  kinds  are  borne  on  the  same  plant  ^ 
as  in  Indian  Corn,  the  Birch,  the  Oak,  Beech,  Hazel,  Hickory,  &c.  if 
and  they  are  called  dioecious  when  borne  by  different  individuals  ;  as 
in  the  Willow  and  Poplar,  the  Sassafras,  the  Prickly  Ash,  the  Hemp 
and  Hop,  Moonseed  (Fig.  413,  414),  &c.  Occasionally,  while  some 
of  the  flowers  are  staminate  only,  and  others  pistillate  only,  a  por- 
tion are  perfect,  the  different  kinds  occurring  either  on  the  same  or 
different  individuals  ;  as  in  most  Palms,  in  many  species  of  Maple, 
&c. :  plants  with  such  flowers  are  said  to  be  polygamous. 

485.  In  some  of  the  blossoms  of  certain  plants  both  stamens  and 
pistils  are  wanting.  This  is  the  case  with  those  that  occupy  the 
margin  of  the  cymes  of  the  Hobblebush  and  some-other  Viburnums, 
and  of  Hydrangea  (Fig.  420),  or  even  with  the  whole  cluster  in 
cultivated  monstrous  states,  as  in  the  Snowball  or  Guelder-Rose 
of  the   gardens  (Viburnum  Opulus).     Here  the   enlarged  corollas 

FIG.  419.     A  staminate  flower  of  Salix  purpurea  (or  monandra),  with  the  stamens  coalescent 
(monadelphous  anil  syngenesious),  so  as  to  appear  like  a  single  one. 


SUPPRESSION    OR    ABORTION    OF    PARTS. 


263 


make  the  whole  blossom.  Such  flowers,  being  neither  staminate 
nor  pistillate,  are  said  to  be  neutral.  In  so-called  compound  flowers 
(394)  the  strap-shaped  marginal  flowers  are  sometimes  neutral,  as 
in  Coreopsis  (Fig.  324,  325),  Mayweed,  and  Sunflower.  In  some 
Grasses  and  other  plants  such  neutral  flowers  want  the  floral  en- 
velopes also,  or  are  reduced  to  an  abortive  rudiment. 


486.  The  suppression  or  abortion  of  a  whole  circle  of  organs  in  a 
symmetrical  flower  does  not  destroy  its  symmetry,  if  we  take  note 
of  the  absent  members.  Thus  a  monochlamydeous  flower,  with  a 
single  full  circle  of  stamens,  usually  has  the  latter  placed  opposite 
the  leaves  of  the  perianth,  that  is,  of  the  calyx,  the  corolla  or  in- 
tervening circle  having  failed  to  appear.  But  when,  with  the  abor- 
tion of  the  primary  circle,  say  of  the  stamens,  we  have  an  augmenta- 
tion of  one  or  more  additional  circles  of  the  same  kind  of  organ,  the 
law  of  alternation  appears  to  be  violated;  the  stamens  that  are 
present,  or  the  outer  circle  of  them,  standing  before  the  petals,  in- 
stead of  alternate  with  them.  It  is  customary  to  assume  this  ex- 
planation for  all  cases  of  the  anteposition  of  the  stamens  to  the  pet- 
als, whether  in  the  Primrose  family,  in  Claytonia,  in  the  Vine  (Fig. 

FIG.  420.     Cyme  of  Hydrangea  arborescens,  with  the  large  marginal  flowers  neutral 


2G4 


THE    FLOWER. 


384),  or  the  Buckthorn,  &c.  But  more  probable  explanations  for 
some  such  cases  have  already  been  given  (459,  4G0).  It  can  no 
longer  be  deemed  sufficient  to  assume  the  obliteration  of  a  normal 
floral  circle,  and  the  production  of  a  second  one,  when  no  traces  of 
the  former  can  be  detected  and  no  clear  analogy  shown  with  some 
strictly  parallel  instance.  Yet  we  may  confidently  apply  this  view 
when  we  do  find  traces  of  obliterated  organs,  as  in  the  Geranium 
family,  for  example.  The  pentamerous  flower  of  Geranium  exhibits 
ten  stamens,  plainly  occupying  two  rows,  the  five  of  the  exterior 
circle  shorter  than  the  others.  One  set  of  these  stamens  alternates 
with  the  petals,  the  other  is  opposed  to  them.  But  on  close  exami- 
nation, we  perceive  that  it  is  the  inner  circle  of  stamens  that  alter- 
nates with  the  petals  ;  those  of  the  outer  circle  stand  directly  before 
them.  This  is  a  not  uncommon  case  where  there  are  just  twice  as 
many  stamens  as  there  are  petals  or  sepals.  In  this  instance  the 
explanation  of  the  anomaly  is  furnished  by 
the  five  little  bodies,  called  by  the  vague  and 
convenient  name  of  glands,  which  stand  on 
the  receptacle  between  the  petals  and  the  sta- 
mens, and  regularly  alternate  with  the  former. 
They  accordingly  occupy  the  exact  position 
of  the  original  stamineal  circle :  wherefore,  as 
421  situation  is  the  best  indication  of  the  nature  of 

organs,  we  may  regard  them  as  the  abortive  rudiments  of  the  five 
proper  stamens,  here  obliterated.  In  the  annexed  diagram  (Fig.  421) 
these  are  accordingly  laid  down  in  the  third  circle,  as  five  small  oval 
spots,  slightly  shaded.  The  actual  stamens  consequently  belong  to 
two  augmented  circles,  those  of  the  exterior  and  shorter  set  of  which 
(represented  by  the  larger,  unshaded  figures),  normally  alternating 
with  the  glands,  are  of  course  opposed  to  the  petals,  and  those  of  the 
inner  and  larger  set,  normally  alternating  with  the  preceding,  neces- 
sarily alternate  with  the  petals.  This  view  is  further  elucidated  by 
the  closely  allied  genus  Erodium,  where  all  the  parts  are  just  the 
same,  except  that  the  five  exterior  actual  stamens  are  shorter  still, 
and  are  destitute  of  anthers  ;  that  is,  the  disposition  to  suppression, 
which  has  caused  the  obliteration  of  the  primary  circle  of  stamens 
and  somewhat  reduced  the   second  in  Geranium,  has   in  Erodium 


FIG.  421.  Diagram  (cross-section )  of  the  flower  of  Geranium  marulatum,  exhibiting  the 
relative  position  of  parts,  especially  the  glands  alternate  with  the  petals,  and  the  two  rows  of 
stamens  within  them. 


SUPPRESSION    OR   ABORTION    OF    PARTS.  2G5 

rendered  the  latter  abortive  also,  leaving  those  of  the  third  row  alone 
to  fulfil  their  proper  office.  And  in  a  South  African  genus,  Monso- 
nia,  five  stamens  actually  occur  in  the  place  of  these  glands,  making 
fifteen  real  stamens,  or  three  circles.  The  general  plan  of  the  flower 
is  the  same  in  the  Flax  family,  except  that  the  glands  which  answer 
to  the  outer  rank  of  stamens  are  still 
less  conspicuous,  and  those  of  the  next 
circle  are  reduced  to  small  abortive 
filaments,  or  to  minute  teeth  in  the 
ring  formed  by  the  union  of  all  the 
filaments  into  a  cup  at  the  base,  leav- 
ing five  perfect  stamens,  which,  though 

they  alternate  with  the  petals  indeed,  belong  to  a  third  circle  (Fig. 
422,  423).  In  a  few  species  of  Flax,  this  second  circle  of  stamens 
is  perfectly  obliterated,  so  that  no  vestige  is  to  be  seen. 

487.  The  complete  suppression  of  two  or  three  of  the  circles  be- 
longing to  the  complete  flower,  and  of  a  part  of  the  members  of  what 
remains,  reduces  a  blossom  to  the  last  degree  of  simplicity.  Among 
the  simplest  of  perfect  flowers  are  those  of  Callitriche  (Fig.  1136- 
1138),  which  have  neither  calyx  nor  corolla;  and  only  one  stamen, 
as  is  expressed  in  the  annexed  diagram  (Fig.  424)  ;  yet  the  four- 

lobed    pistil    shows 
that  the  blossom  was 

constructed   on    the 
o 
o         plan  of  four.     And 

424  "1      Zs      X  ^      S      X        even  this  stamen  is 

suppressed  in  cer- 
tain blossoms,  and  the  pistil  in  others.  In  Euphorbia  (also  to  be 
illustrated  under  the  family  to  which  it  belongs,  Fig.  1143)  the 
flowers  are  always  separated,  and  the  staminate  blossom  is  reduced  to 
a  single  stamen,  the  pistillate  to  a  single  three-lobed  pistil  (Fig.425). 
And  in  the  Willow,  as  already  noticed  (438),  the  pair  of  stamens 
which  represents  one  sort  of  blossom,  and  the  single  pistil  which  repre- 
sents the  other,  are  widely  separated,  being  borne  on  distinct  trees. 

FIG.  422.    Flower  of  Linuni  perenne.    423.  Its  stamens  and  pistils  enlarged. 

FIG.  424.  Diagram  of  a  perfect  flower  of  Callitriche,  with  no  floral  envelopes,  one  stamen, 
and  a  four-celled  pistil. 

FIG.  425.  Diagram  of  the  moncecious  flowers  of  Euphorbia :  o,  the  pistillate  flower  re- 
duced to  a  mere  three-celled  pistil ;  and  b,  one  of  the  staminate  flowers  reduced  to  a  single 
stamen. 

FIG.  426.  Diagram  of  the  dioecious  flowers  of  the  Willow  :  a,  one  of  the  pistillate  flowers 
reduced  to  a  solitary  pistil ;  6,  a  staminate  flower  reduced  to  a  pair  of  stamens. 

23 


as  &    .   o 


266 


THE    FLOWER. 


4S8.  Unusual  States  of  the  Receptacle.     The  receptacle  (421)  is 

commonly  small,  short,  and  inconspicuous,  being  merely  the  extrem- 
ity of  the  flower-stalk  upon  which  the  sev- 
eral organs  are  inserted  (Fig.  343).     Some- 
times, however,  it  is  remarkably  enlarged 
or  elongated.     A  striking  instance  of  an  en- 
larged receptacle  is  found  in  Nelumbium, 
where  it  is  dilated  into  a  large  top-shaped 
body,  nearly  enclosing  the    pistils   in    sep- 
arate cavities  (Fig.  427).      Whenever  the 
pistils  of  a  flower  are  very  numerous,  the 
receptacle  is  more  or  less  enlarged  for  their 
insertion,    as    in    Magnolia,    the    Raspberry    and   Blackberry,  &c. 
In  the   Strawberry  the  enlarged  and  conical 
receptacle  (Fig.   428),  bearing  the   pistils  on 
its    surface,   becomes    the    edible   portion   in 
fruit.    In  the  Rose  (Fig. 
429)    the  receptacle  is 
deeply  concave,  instead 
of  convex,   being    urn- 
shaped,  invested  by  the 
adnate  tube  of  the  calyx, 
and  bearing  the   petals 
and  stamens  on  its  bor- 
der and  the  numerous 
pistils  on  its  whole  hol- 
low surface  (Fig.  429). 
It  is  much  the  same  in 
Calycanthus  (Fig.  814- 
819).  In  Geranium,  and  423 

many  allied  plants,  the  receptacle  is  prolonged  between  the  ovaries, 
and  coheres  with  their  styles  (Fig.  430)  ;  these,  however,  separating 
at  maturity  (Fig.  431).  In  Umbelliferous  plants  a  similar  but  more 
slender  prolongation  of  the  receptacle  is  extended  upwards  between 
the  contiguous  faces  of  the  two  united  ovaries  which  form  the  fruit 

FIG.  427.  The  enlarged,  top-shaped  receptacle  of  Nelumbium,  bearing  the  pistils,  im- 
mersed in  hollows  of  its  upper  face. 

FIG.  428.    Longitudinal  section  of  a  young  strawberry,  enlarged. 

FIG.  429.     Similar  section  of  a  young  Rose-hip. 

FIG.  430.     Gynaecium  of  Geranium  maculatum,  or  Cranesbill,  enlarged. 

FIG.  431.  The  same  at  maturity,  with  the  fire  pistils  splitting  away  from  the  long  beak  or 
receptacle  and  hanging  from  its  top  by  their  styles. 


THE    RECEPTACLE,    DISK,    ETC. 


267 


in  that  family.  Occasionally  one  or  more  of  the  internodes  between 
successive  floral  circles  elongate ;  as  between  the  calyx  and  the 
corolla  in  Pinks,  and  especially  in  Silene,  forming  a  stalk  within  the 
calyx,  on  which  the  rest  of  the  flower  is  raised  (Fig.  432)  ;  while 
in  many  Gentians  the  inter- 
node  above  the  circle  of 
stamens  is  developed,  rais- 
ing the  pod  on  a  stalk  of  its 
own.  This  is  a  common 
case  in  the  Caper  family ; 
in  which  the  genus  Gynan- 
dropsis  (Fig.  433)  exhibits 
a  remarkable  development 
of  the  whole  receptacle.  It 
is  enlarged  into  a  flattened 
disk,  where  it  bears  the  pet- 
als, and  is  then  prolonged  4S2 

into  a  conspicuous  stalk  which  bears  the  stamens,  —  or  rather,  to 
which  the  bases  of  the  stamens  are  adnate,  —  and  then  into  a  shorter 
and  more  slender  stalk  for  the  pistil ;  thus  separating  the  four  circles 
or  sets  of  organs,  like  so  many  whorls  of  verticillate  leaves.  The 
general  name  for  this  kind  of  stalk,  as  contradistinguished  from  the 
pedicel  or  stalk  of  the  flower,  is  the  Stipe  ;  and  whatever  organ  or 
set  of  organs  is  thus  elevated  is  said  to  be  stipitate.  Whenever  it  is 
necessary  to  particularize  the  portion  of  the  receptacle  thus  devel- 
oped, the  stipe  is  termed  the  Anthophore  when  it  appears  just  above 
the  calyx,  and  elevates  the  petals,  stamens,  and  pis- 
tils ;  the  Gonophore,  when  it  supports  both  the  sta- 
mens and  pistils  ;  and  the  Gynophore,  Gynobase,  or 
Carpophore,  when  it  bears  the  gynajcium  alone.  The 
stalk  which  sometimes  supports  each  simple  pistil  of  the 
gynrecium  (as  in  Coptis  or  the  Goldthread)  is  called 
a  Thecaphore.  This,  however,  does  not  belong  to  the 
receptacle  at  all,  but  to  the  pistil  itself,  and  is  ho- 
mologous with  the  leafstalk.  «4 

489.  A  Disk  is  a  part  of  the  receptacle,  or  a  growth  from  it,  en- 
larged under  or  around  the  pistil.     Like  the  other  parts  of  the  flower, 

FIG.  432.     Section  of  a  flower  of  Silene  Pennsylvania,  showing  the  stipe  or  anthophore. 
FIG.  433.     Flower  of  Gynandropsis,  with  a  remarkably  elongated  receptacle. 
FIG.  434.     Disk  of  the  Orange,  underneath  the  pistil  (hypogynous). 


2GS  THE   KLOWElt. 

it  is  hypogynous  (4GG),  when  free  from  all  union  either  with  the  pis- 
til or  the  calyx,  as  in  the  Rue  and  the  Orange  (Fig.  434).  It  is 
perigynous  (4G7),  when  it  adheres  to  the  hase  of  the   calyx,  as 

in  the  Buckthorn  (Fig.  435, 
436)  ;  and  where  the  calyx  is 
adnate  to  the  ovary,  as  in  the 
Apple,  Hawthorn  (Fig.  390), 
&c.,  there  is  commonly  a  disk  in- 
terposed between  the  two.  The 
disk  is  sometimes  expanded  on 
the  summit  of  such  an  ovary,  when  it  is  said  to  he  epigynous  (469), 
as  in  Cornus,  and  all  Umbelliferous  plants. 


Sect.  V.     The  Floral  Envelopes  in  Particular. 
490.  Their  Development,  or  Organogeny,  first  requires  a  brief  notice. 

The  flower-bud  is  formed  in  the  same  way  as  the  leaf-bud ;  and 
what  has  been  stated  as  to  the  fonnation  of  the  leaves  of  the  branch 
(273)  equally  applies  to  the  leaves  of  the  flower.  The  sepals  are 
necessarily  the  earliest  to  appear,  which  they  do  in  the  form  of  so 
many  cellular  protuberances,  at  first  distinct,  inasmuch  as  then  their 
tips  only  are  eliminated  from  the  axis.  Each  one  may  complete  its 
development  separately,  like  an  ordinary  leaf,  when  the  sepals  re- 
main distinct.  Or  the  lower  and  later-eliminated  portions  of  the 
forming  organs  of  the  circle  coalesce  as  they  grow  into  a  ring,  which, 
further  developed  in  union,  forms  the  cup  or  tube  of  the  gamophyl- 
lous  calyx.  In  some  cases,  it  would  appear  that  the  sepals  may  at 
first  grow  separately,  and  afterwards,  though  only  at  a  very  early 
period,  coalesce  by  the  cohesion  of  their  contiguous  parts.  The  sev- 
eral parts  of  an  irregular  calyx  are  at  first  equal  and  similar  ;  the 
irregularity  appears  in  their  subsequent  unequal  growth.  The  pet- 
als or  parts  of  the  corolla  originate  in  the  same  way,  a  little  later 
than  the  sepals.  Their  coalescence  in  the  gamopetalous  corolla  is 
congenital ;  the  ring  which  forms  its  tube  appearing  nearly  as  early 
as  do  the  slight  projections  which  become  its  lobes  and  answer  to  the 
summits  of  the  component  petals.  The  rudiments  of  the  petals  are 
visible  earlier  than  those  of  the  stamens  :  but  their  growth  is  at  first 

FIG.  435.     Flower  of  a  Buckthorn,  showing  a  large  perigynous  disk.     436.  Vertical  section 
of  the  same. 


AESTIVATION    OR    PIMiFLOKATION.  269 

retarded,  so  that  the  stamens  are  earlier  completed,  and  their 
anthers  surpass  them,  or  often  finish  their  growth,  while  the  petals 
are  still  minute  scales  :  at  length  they  make  a  rapid  growth,  and 
enclose  the  organs  that  belong  above  or  within  them.  Unlike  the 
sepals  in  this  respect,  the  base  of  the  petal  is  frequently  narrowed 
into  a  portion  which  corresponds,  more  or  less  evidently,  to  the 
petiole  (the  claw),  and  which,  like  the  petiole,  does  not  appear  until 
some  time  after  the  blade  or  expanded  part ;  the  summit  being  al- 
ways the  earliest  and  the  base  the  latest  portion  formed.  As  the 
envelopes  of  the  flower  grow  and  expand,  those  of  each  circle  adapt 
themselves  to  each  other  in  various  ways,  and  acquire  the  relative 
positions  which  they  occupy  in  the  flower-bud.  Their  arrangement 
in  this  state  is  termed 

491.  Their  Estivation  or  Prrcfloration.    The  latter  would  be  the 

preferable  term ;  but  the  former  is  in  common  use  ;  the  word  Esti- 
vation (literally  the  summer  state)  having  been  devised  for  the 
purpose  by  Linnreus ;  —  for  no  obvious  reason  except  that  he  had 
already  applied  the  name  of  Vernation  (the  spring  state)  to  express 
the  analogous  manner  in  which  leaves  are  disposed  in  the  leaf-bud. 
The  same  terms  are  employed,  and  in  nearly  the  same  way,  in  the 
two  cases,  but  with  some  peculiarities.  As  to  the  disposition  of 
each  leaf  taken  by  itself,  the  corresponding  terms  of  vernation  (257) 
wholly  apply  to  aestivation.  The  arrangement  in  the  bud  of  the 
several  members  of  the  same  floral  circle  in  respect  to  each  other,  is 
of  much  importance  in  systematic  botany,  on  account  of  the  nearly 
constant  characters  that  it  furnishes,  and  also  in  structural  botany, 
from  the  aid  it  often  affords  in  determining  the  true  relative  super- 
position or  succession  of  parts  on  the  axis  of  the  flower,  by  observ- 
ing the  order  in  which  they  overlie  or  envelope  each  other. 

492.  The  various  forms  of  aestivation  that  have  been  distinguished 
by  botanists  may  be  reduced  to  three  essential  kinds,  namely,  the 
imbricative,  the  contorted  or  convolutive,  and  the  valvular.* 

493.  Imbricative  aestivation,  in  a  general  sense,  comprises  all 
the  modes  of  disposition  in  which  some  members  of  a  floral  circle 
are  exterior  to  the  others,  and  therefore  overlie  or  enclose  them  in 


*  "We  should  properly  say  of  the  (estivation  that  it  is  imbricative,  eonvolutive, 
valvular,  &c,  and  of  the  calyx  and  corolla,  or  of  the  sepals,  &c,  that  they  arc 
imbricate  or  imbricated,  convolute,  valvate,  &c.  in  aestivation ;  but  such  precision 
of  language  is  seldom  attended  to. 


270 


THE    FLOWER. 


the  bud.  This  must  almost  necessarily  occur  wherever  the  parts 
are  inserted  at  distinguishable  different  heights,  and  is  the  natural 
result  of  a  spiral  arrangement.  The  name^fc  most  significant  when 
successive  leaves  are  only  partially  covered  by  the  preceding,  as  in 
Fig.  207.  Here  they  manifestly  break  joints,  or  are  disposed  like 
tiles  or  shingles  on  a  roof,  as  the  term  imbricated  denotes.  It  is 
therefore  equivalent  to  the  spiral  arrangement :  and,  on  the  other 
hand,  we  properly  apply  the  term  imbricated  to  any  continuous 
succession  of  such  partly  overlying  members ;  as  when  we  say  of 
appressed  and  crowded  leaves  that  they  are  imbricated  on  the  stem, 
or  thus  express  the  whole  arrangement  of  the  scales  of  a  bud 
(Fig.  153),  or  a  bulb  (Fig.  172),  or  of  a  catkin  or  cone  (Fig.  209). 
The  alternation  of  the  petals  with  the  sepals,  &c.  necessarily 
renders  the  floral  envelopes  likewise  imbricated  in  the  bud,  taken  as 
a  whole.  But  in  proper  aestivation,  what  we  have  to  designate  is 
the  arrangement  of  the  parts  of  the  same  floral  circle  (say  the  five 
sepals  or  the  five  petals)  in  respect  to  each  other. 

494.  Now  when  the  sepals  or 
-^===5;^  ^?s===:tv  *ne  Pe*a^s  are  three  in  number, 

/^        "\\        /v^^====X\\        anc^  are  regulai'ty  imbricated  in 

" "     Ul  m\    lhc  bud'  as  in  Fi°'  437' tlie  tliree 

leaves   are    arranged  just  as  in 
three-ranked    phyllotaxis     (238, 
«7  438  Fig.  203)  ;  that  is,  with  the  first 

petal  exterior  to  the  others,  the  second  is  covered  by  the  first  on 
one  side  while  it  covers  the  third  on  the  other.  When  they  are  five 
(as  in  the  calyx  of  Geranium,  Fig.  439),  they  are  disposed  just  as  in 
five-ranked  or  quincuncial  phyllotaxis  with  the 
axis  shortened  (240,  Fig.  20G) ;  viz.  two  leaves 
are  exterior,  two  wholly  interior,  and  one  (the 
third)  with  one  edge  covered  by  No.  1  on  one 
side  while  it  covers  No.  5  with  its  other  edge.  So 
that  this,  the  regular  mode  of  imbrication  when 
the  parts  are  in  fives,  is  termed  quincuncial  aes- 
tivation, or  the  parts  are  said  to  be  quincuncially 


FIG.  437.  Diagram  of  a  three-leaved  (trimerous)  calyx  and  corolla,  both  imbricated  in 
aestivation. 

FIG  438.  Diagram  of  the  estivation  of  three  petals  (or  one  circle  of  the  petals)  of  Magno- 
lia,  similarly  imbricated,  but  strongly  enwrapping,  each  making  nearly  a  circle. 

FIG.  439.  Diagram  of  the  imbricative  aestivation  of  the  calyx  and  the  convolutive  aestiva- 
tion of  the  corolla  of  Geranium  ;  the  sepals  numbered. 


^estivation  or  pr^efloration.     m  271 

imbricated.  We  have  here  the  advantage  of  being  able  to  number 
the  successive  sepals,  or  petals,  since  the  third  leaf  is  not  only  recog- 
nizable by  its  iutajdWiaR  position,  but  also  indicates  the  direction 
in  which  the  spfl  BEJS-  20G  and  Fig.  439). 

495.  It  must  ber^WI  Weed,  in  the  comparison,  that  the  parts  of 
successive  cycles  are  superposed  in  the  foliage,  while  those  of  the 
floral  circles  alternate.  Regular  imbrication  in  the  4-merous  flower 
gives  two  outer  and  two  inner  members  in  aestivation  (as  in  the 
calyx  of  Cruciferous  blossom-;,  Fig.  3G7),  on  the  principle  of  two 
decussating  pairs  of  leaves  (441)  ;  or  it  may  sometimes  be  refer- 
able to  a  modification  of  some  alternate  spiral  arrangement. 

496.  The  degree  of  overlapping  depends  upon  the  breadth  of  the 
parts  and  the  state  of  the  bud  ;  it  naturally  grows  less  and  less  as 
the  bud  expands  and  is  ready  to  open.  It  is  from  the  full-grown 
flower-bud,  just  before  anthesis  (or  the  .opening  of  the  blossom),  that 
our  diagrams  are  usually  taken  ;  in  which  the  parts  are  represented 
as  moderately  or  slightly  overlapping.  The  same  overlapping  car- 
ried to  a  greater  extent  will  cause  the  outer  leaf  to  envelope  all  the 
rest,  and  each  succeeding  one  to  envelop  those  within  ;  as  shown  in 
Fig.  438  from  one  circle  of  petals  of  a  Magnolia  taken  in  an  early 
state  of  the  bud.  To  this,  however,  has  not  improperly  been  applied 
the  name  of  convolute,  from  its  similarity  to  the  convolute  vernation 
of  the  leaves  of  the  branch  (257),  similarly  rolled  up  one  within  the 
other.  But  it  is  practically  inconvenient,  and  wrong  in  principle,  to 
designate  different  degrees  of  the  very  same  mode  by  distinct  names  ; 
furthermore,  it  is  to  the  next  general  mode  of  aestivation  that  the 
name  of  convolute  is  more  commonly  applied,  at  least  in  recent  sys- 
tematic botanical  writings. 

497.  There  are  numerous  cases  of  imbricative  aestivation,  espe- 
cially in  irregular  flowers,  where  the  overlapping  of  parts  does  not 
altogether  accord  with  what  must  needs  be  their  order  of  succes- 
sion on  the  axis.  In  the  5-merous  calyx  and  corolla  of  all  truly 
papilionaceous  flowers,  for  example,  one  edge  of  the  sepal  or  the 
petal  No.  2  is  placed  under,  instead  of  over,  the  adjacent  edge  of 
No.  4,  in  consequence  of  which  three,  instead  of  only  one,  of  the 
leaves  have  one  edge  covered  and  the  other  external ;  as  is  shown 
in  Fig.  358.  Since,  in  the  corolla  of  this  kind  of  blossom,  the  ex- 
terior petal,  here  the  vexillum  (472),  is  the  larger,  and  at  first  em- 
braces all  the  rest,  this  modification  of  imbricative  aestivation  has 
received  the  name  of  vexillary.     As  nearly  the  same   thing  occurs 


272 


THE   FLOWER. 


^^ 


in  the  Violet,  it  is  probably  caused  by  some  slight  dislocation  that 
takes  place  during  the  early  growth  of  organs  in  the  irregular  blos- 
som.    It  is  not  restricted  to  irregular  flowers,  however,  but  occurs 
as  a  casual  variation,  or  perhaps  more  frequent- 
ly than  the  quincuncial,  in  the  regular  corolla 
of  the  Linden  (as  is  shown  in  Fig.  440).     A 
slight  obliquity  in  the  position  of  the  petal  No. 
2,  assumed  at  an  early  period,  would  account 
for  the  whole  anomaly.     That  this  suggests 
the  true  explanation  is  almost  demonstrated  by 
440  the  varying  aestivation  of  the  corolla  of  the 

Linden ;  in  which  the  same  bunch  of  blossoms  often  furnishes  in- 
stances of  regular  quincuncial  imbrication,  of  the  modification  here 
referred  to,  and  of  a  similar  disposition  of  the  fifth  petal,  throwing 
one  of  its  edges  outwards  also.  If  the  first  petal  were  also  to  par- 
take of  this  slight  obliquity,  the  imbricative  would  be  completely 
converted  into  what  is  variously  named 

498.  The  contorted,  twisted,  or  convolutive  aestivation  (Fig.  439, 
441,  the  corolla,  and  442).  In  this  mode,  the  leaves  of  the  circle  are 
all,  at  least  apparently,  inserted  at  the  same  height,  and  all  occupy 
the  same  relative  position :  one  edge  of  each,  being  directed  ob- 
liquely inwards,  is  covered  by  the  adjacent  leaf  on  that  side,  while 
the  other  covers  the  corresponding  margin  of  the  contiguous  leaf  on 
the  other  side.  This  is  owing  to  a  torsion  or  twisting  of  each  member 
on  its  axis  early  in  its  development ;  so  that  the  leaves  of  the  floral 
verticil,  instead  of  forming  arcs  of  a  circle,  or  sides  of  a  polygon 


having  for  its  centre  that  of  the  blossom,  severally  assume  an  oblique 
direction,  by  which  one  edge  is  carried  partly  inward  and  the  other 
outward.     This  contorted  aestivation  is  rare  in  the  calyx,  but  com- 


FIG.  440.     Diagram  of  the  plan  and  restivation  of  the  flower  of  the  Linden. 

FIG.  441.  Diagram  of  the  imbricated  calyx  of  Wallflower  (two  outer  and  two  inner  sepals), 
and  within  the  strongly  contorted  or  convolute  corolla.  442.  Corolla  of  the  latter  more  open. 
443.  Cross-section  of  the  plaited  tube  of  the  corolla  of  Campanula.  444.  Similar  section  of  the 
plaited  and  supervolute  corolla  of  CoutoIvuIus. 


AESTIVATION    OB    PR;EFLORATION.  273 

mon  enough  in  the  corolla.  When  this  obliquity  of  position  is  stromr, 
the  petals  themselves  are  usually  oblique,  or  unequal-sided,  from  the 
lesser  growth  of  the  overlapped  side.  This  is  well  seen  in  the  pet- 
als of  most  Malvaceous  plants,  and  in  those  of  the  St.  Johnswort.  In 
the  Pink,  however,  and  in  many  other  instances,  the  petals  are 
symmetrica],  although  strongly  convolute  in  aestivation.  When  the 
petals  are  broad,  this  convolute  arrangement  is  frequently  conspicu- 
ous in  the  fully  expanded  flower,  as  well  as  in  the  bud.  The  con- 
volution in  the  bud  is  often  so  great,  that  the  petals  appear  as  if 
strongly  twisted  or  rolled  up  together,  each  being  almost  completely 
overlapped  by  the  preceding,  so  that  they  become  convolute  nearly 
in  the  sense  in  which  the  term  is  used  in  vernation  ;  as  in  the  Wall- 
flower (Fig.  441,  442).  Although  there  is  some  diversity  of  usage, 
the  terms  convolute  and  contorted  in  aestivation  are  now  for  the  most 
part  employed  interchangeably,  or  nearly  so. 

499.  The  valvular  or  valvate  aestivation  is  that  in  which  the  parts 
of  a  floral  circle  are  placed  in  contact,  edge  to  edge,  throughout  their 
whole  length,  without  any  overlapping,  as  in  the  calyx  of  the  Mal- 
low and  Linden,  Fig.  440.  Here  the  members  of  the  circle  stand  in 
an  exact  circle,  no  one  being  in  the  least  degree  lower  or  exterior. 
The  edges  of  the  sepals  or  petals  in  tins  case  are  generally  abrupt, 
or  as  thick  as  the  rest  of  the  organ  ;  by  which  mark  the  valvate  aes- 
tivation may  commonly  be  recognized  in  the  expanded  flower. 

500.  By  inflexion  of  the  edges,  the  valvate  aestivation  passes  by 
gradations     into    the    induplicate    (Fig. 

445),  and  this,  when  the  margins  are  in-       /^fjL  f^pl 

rolled,  into  the  involute  (Fig.  446),  as  is      ((  ^^  (o)  ^ 

exemplified  by  the  calyx  of  different  spe- 
cies of  Clematis.     On  the  other  hand,  the 
valvate  calyx  of  many  Malvaceous  plants 
has  the  margins  projecting  outwards  into  salient  ridges,  or  is  redupli- 
cate, in  aestivation. 

501.  In  the  Mignonette,  and  some  other  flowers,  the  aestivation  is 
open  ;  that  is,  the  calyx  and  corolla  are  not  closed  at  all  over  the 
other  parts  of  the  flower  in  the  bud. 

502.  The  form  of  the  tube  of  the  calyx  or  corolla  in  the  bud 
sometimes  has  to  be  considered.  Sometimes  it  is  plicate,  or  plaited 
'lengthwise  ;  and  the  plaits  may  be  turned  either  inwards,  as  in  the 

FIG.  445.     Diagram  of  the  valvate-iuduplicate  aestivation  of  the  calyx  of  Clematis  Virgini- 
ana.     44G.  Same  of  Clematis  Viticella,  the  margins  involute. 


274 


THE    FLOWKR. 


corolla  of  Gentians,  or  outwards,  as  in  that  of  Campanula  (Fig.  443). 
When  these  plaits  are  laid  over  one  another  in  a  convolute  manner, 
as  in  the  unopened  corolla  of  the  Morning-Glory 
(Fig.  444)  and  Stramonium  (Fig.  447,  448),  the 
aestivation  is  said  to  be  supervolute. 

503.  The  direction  of  the  spire  or  the  overlap- 
ping of  parts  may  be  either  from  left  to  right,  or 
from  right  to  left ;  and  this  direction  is  generally 
uniform.  In  indicating  the  direction,  it  is  most 
natural  to  suppose  the  observer  to  stand  before 
the  flower-bud.  DeCandolle,  indeed,  supposes  the 
observer  to  occupy  the  centre  of  the  flower,  Avhich 
would  reverse  the  direction  ;  but  the  former  is  the 
prevalent  view.  The  direction  is  frequently  re- 
versed in  passing  from  the  calyx  to  the  corolla, 
sometimes  with  remarkable  uniformity ;  while 
again  the  two  occur  almost  indifferently  in  many 
cases.  The  kind  of  aestivation,  although  often  the  same  both  in  the 
calyx  and  corolla,  —  as  in  Parnassia  (Fig.  381)  and  Elodea  (Fig. 
375),  where  both  are  quincuncially  imbricated,  —  is  as  frequently 
different ;  and  the  difference  is  often  characteristic  of  families  or 
genera.  Thus,  the  calyx  is  valvate  and  the  corolla  convolute  in 
all  Malvaceae  ;  the  calyx  imbricated  and  the  corolla  convolute  in 
Hypericum,  in  the  proper  Pink  tribe,  &c.  Solitary  exceptions  now 
and  then  occur  in  a  family.  Thus,  the  corolla  in  Rosacea?  is  imbri- 
cated, so  far  as  known,  except  in  Gillenia,  where  it  is  convolute.  In 
general  it  may  be  said,  that  the  aestivation  of  the  corolla  is  less  con- 
stant than  that  of  the  calyx. 

504.  The  Calyx.  In  treating  of  the  general  structure  and  diver- 
sities of  the  flower,  we  have  already  noticed  the  principal  modifi- 
cations of  the  calyx  and  corolla,  as  well  as  many  of  the  terms  em- 
ployed to  designate  them ;  which  need  not  be  here  repeated. 

505.  The  number  of  sepals  that  enter  into  the  composition  of  a 
calyx  is  indicated  by  adjectives  formed  from  the  corresponding 
Greek  numerals  prefixed  to  the  name ;  as,  disepalous,  for  a  calyx  of 
two  sepals  ;  trisepalous,  of  three  sepals  ;  tetrasepalous,  of  four  ;  pen- 
(asepalous,  of  five ;  hexasepalous,  of  six  sepals  ;  and  so  on.  Very 
commonly,  however,  the   Greek  word  for  leaves,  phylla,  is  used  in 


FIG    447.     Summit  of  the  unexpanded  corolla  of  Datura  meteloides.    448.  Transverse  sec- 
tion of  the  same. 


THE  CALYX  AND  COKOLLA.  275 

such  composition  ;  and  the  calyx  is  said  to  be  diphyllous,  triphyllous, 
tetraplnjllous,  pentaphyllous,  hexaphyllous,  &c,  according  as  it  is  com- 
posed of  two,  three,  four,  five,  or  six  leaves  or  sepals  respectively. 
These  terms  imply  that  the  leaves  of  the  calyx  are  distinct,  or  nearly 
so.  When  they  are  united  into  a  cup  or  tube,  the  calyx  was  by  the 
earlier  botanists  incorrectly  said  to  be  monophyllous  (literally  one- 
leaved)  ;  —  a  term  which  Ave  continue  to  use,  guarding,  however, 
against  the  erroneous  idea  which  its  etymology  involves,  and  bearing 
in  mind  that  the  older  technical  language  in  botany  is  founded  upon 
external  appearance,  and  not  the  real  structure,  as  we  now  under- 
stand it.  The  correct  term,  calyx  gamophyllous,  is  now  coming  into 
use  :  this  literally  expresses  the  true  state  of  the  case,  and  is  equiva- 
lent to  the  phrase  sepals  united ;  the  degree  of  coalescence  being  in- 
dicated by  adding  "  at  the  base,"  "  to  the  middle,"  or  "  to  the  sum- 
mit," as  the  case  may  be.  Still,  in  botanical  descriptions,  it  is  usual 
and  ordinarily  more  convenient  to  regard  the  calyx  as  a  whole,  and 
to  express  the  degree  of  union  or  separation  by  the  same  terms  as 
those  which  designate  the  degree  of  division  of  the  blade  of  a  leaf 
(281  —  287)  :  as,  for  example,  Calyx  Jive-toothed,  when  the  sepals  of 
a  pentaphyllous  calyx  are  united  almost  to  the  top  ;  Jive-cleft,  when 
united  to  about  the  middle  ;  Jive-parted,  when  they  are  separate 
almost  to  the  base  ;  and  Jive-lobed,  for  any  degree  of  division  less 
than  five-parted,  without  reference  to  its  particular  extent. 

506.  The  united  portion  of  a  gamophyllous  calyx  is  called  its 
tube  ;  the  distinct  portions  of  the  sepals  are  termed  the  teeth,  seg- 
ments, or  lobes,  according  to  their  length  as  compared  with  the  tube  ; 
and  the  orifice  or  summit  of  the  tube  is  named  the  throat.  The 
calyx  is  said  to  be  entire,  when  the  leaves  of  the  calyx  are  so  com- 
pletely confluent  that  the  margin  is  continuous  and  even.  The  terms 
regular  and  irregular  (44G,  471)  ai*e  applied  to  the  calyx  or  corolla 
separately,  as  well  as  to  the  Avhole  flower.  The  counterpart  term  to 
calyx  monophyllous  or  monosepalous,  is  polyphyllous  or  polysepalous 
(viz.  of  many  leaves  or  sepals).  This  is  equivalent  to  the  phrase 
sepals  distinct  ;  and  does  not  mean,  as  the  etymology  might  lead 
one  to  suppose,  that  they  arc  unusually  numerous. 

507.  The  Corolla  has  corresponding  terms  applied  to  its  modifica- 
tions. When  its  petals  are  distinct  or  unconnected,  it  is  said  to  be 
polypetalous  ;  when  united,  at  least  at  the  base,  monopetalous,  or 
more  properly  gamopetalous,  as  already  explained.  Various  de- 
grees of  such  union  are  shown  in  Fig.  450  -  4G0.     The  united  por- 


276 


THE    FLO  AVER. 


tions  in  the  latter  case  form  the  tube  of  the  corolla ;  the  distinct  parts 
are  the  lobes,  segments,  &c. ;  and  the  orifice  is  called  the  throat, 
just  as  in  the  calyx.  The  number  of  parts  that  compose  the  corolla 
is  designated  in  the  manner  ah'eady  mentioned  for  the  calyx ;  viz. 
a  corolla  of  two  petals  is  dipetalous  ;  of  three,  tripetalous  ;  of  four, 
tetrapetcdous  ;  of  five, pentapetalous  ;  of  six,  hexapetcdous  ;  of  seven, 
hepta]jetalous  ;  of  eight,  octopetalous  ;  of  nine,  enneapetalous  ;  often, 
decapetalous. 

508.  Frequently  the  petals  (and  rarely  the  sepals)  taper  into  a 
stalk  or  narrow  base,  analogous  to  the  petiole  of  a  leaf,  which  is 
called  the  claw  (unguis)  ;  and  hence  the  petal  is  said  to  be  unguicu- 
late ;  as  in  Crucifei-ous  flowers  (Fig.  405),  the  Pink  family  (Fig. 
432),  and  Gynandropsis  (Fig.  433),  &c. ;  the  expanded  portion,  like 
that  of  the  leaf,  being  distinguished  by  the  name  of  the  lamina,  limb, 
or  blade. 


509.  Some  kinds  of  polypetalous  flowers  receive  particular  names, 
from  the  form  or  arrangement  of  their  floral  envelopes,  especially  of 
the  corolla.  They  may  be  divided  into  the  regular  and  the  irregular, 
—  terms  which  have  already  been  defined  (446,  471).  Among  the 
regidar  forms  we  may  mention  the  rosaceous  flower,  like  that  of  the 
Rose,  Apple,  &c,  where  the  five  spreading  petals  have  no  claws,  or 
very  short  ones  ;  the  liliaceous,  of  which  the  Lily  is  the  type,  where 
the  claws  or  base  of  the  petals  or  sepals  are  erect,  and  gradually 
spread  towards  their  summits  ;  the  caryophyllaceous,  as  in  the  Pink 
and  its  allies  (Fig.  449),  where  the  five  petals  have  long  and  narrow 

FIG.  449.     Corolla  of  Soapwort,  of  five  separate,  long-clawed  or  unguiculate  petals. 

FIG.  450.  Flower  of  Gilia  or  Ipomopsis  coronopifolia ;  the  parts  answering  to  the  claws  of 
the  petals  of  the  last  figure  here  all  united  into  a  tube. 

FIG.  451.  Flower  of  the  Cypress-Afine  ;  the  petals  a  little  farther  united  into  a  five-lobed 
ppreading  border. 

FIG.  452.  Flower  of  the  small  Scarlet  Morning-Glory,  the  five  petals  it  is  composed  of  per- 
fectly united  into  a  trumpet-shaped  tube,  and  a  nearly  entire  spreading  border. 


THE    COROLLA. 


277 


claws,  which  are  enclosed  in  the  tube  of  the  calyx  ;  and  the  cruciate, 
or  cruciform,  which  gives  its  name  to  the  Mustard  family,  where 
the  four  unguiculate  petals,  diverging  equally  from  one  another, 
are  necessarily  disposed  in  the  form  of  a  cross,  as  in  the  Mustard 
(Fig.  405).      Among 

the  irregular  polypeta-  /7/1 ^J— \ 

lous  flowers,  which  are 
extremely  varied  in 
different  families,  the 
papilionaceous  or  but- 
terfly-shaped corolla  of  the  Pulse  family  is  the  most  familiar,  and 
has  already  been  illustrated  (471,  Fig.  392). 

510.  Several  forms  of  the  gamopetalous  corolla,  or  gamophyl- 
lous  calyx,  have  been  distinguished  by  particular  names.  These 
are  likewise  divided  into  the  regular,  where  their  parts  are  equal  in 
size,  or  equally  united ;  and  the  irregular,  where  their  size  or  de- 
gree of  union  is  unequal  (471).  Among  the  former  are  the  cam- 
panulate  or  bell-shaped,  as  the  corolla  of  the  Harebell  (Fig.  456), 
which  enlarges  gradually  and  regularly  from  the  base  to  the  summit ; 


the  infundibuliform,  or  funnel-shaped,  where  the  tube  enlarges  very 
gradually  below,  but  expands  widely  at  the  summit,  as  in  the  corolla 
of  Morning-Glory  (Fig.  1035  and  452)  ;  tubular,  where  the  form  is 
somewhat  cylindrical  throughout,  as  in  Trumpet  Honeysuckle  ;  hypo- 
craterifarm  (more  correctly  hypocraterimorphous),  or  salver-shaped, 

Rotate   or  wheel-shaped  and  five-parted  corolla  of  the  Bittersweet    (Solarium 


FIR.  453. 
Dulcamara). 
FIR.  454. 
FIR.  455. 
FIR.  456. 


Wheel-shaped  and  five-cleft  corolla  of  the  common  Potato. 

The  almost  entire  and  open  bell-shaped  corolla  of  a  Ground  Cherry  (Physalis,). 

Campanulate  corolla  of  the  Harebell,  Campanula  rotundifolia.  45".  Salver- 
shaped  corolla  of  Phlox.  458.  Labiate  (ringent)  corolla  of  Lamium  ;  a  side  view.  459.  Per- 
sonate corolla  of  Antirrhinum.     460.  Personate  corolla  of  Linaria,  spurred  at  the  base. 

24 


278  THE    FLOWEK. 

where  the  limb  spreads  at  right  angles  with  the  summit  of  the  more 
or  less  elongated  tube,  as  in  the  corolla  of  Cypress-Vine  (Fig.  451) 
and  Phlox  (Fig.  457) ;  and  rotate,  or  wheel-shaped,  when  a  hypo- 
crateriform  corolla  has  a  very  short  tube,  as  in  the  Forget-me-not,  Bit- 
tersweet (Fig.  453),  and  Potato  (Fig.  454). 

511.  The  principal  irregular  gamopetalous  or  gamophyllous  forms 
that  have  received  a  separate  appellation  are  the  ligulate  or  strap- 
shaped,  winch  has  already  been  explained  (473),  and  the  labiate  or 
bilabiate.  The  latter,  as  already  stated,  is  produced  by  the  unequal 
union  of  the  sepals  or  petals  (473),  so  as  to  form  an  upper  and  a  lower 
part,  or  two  lips,  as  they  are  called,  from  an  obvious  resemblance  to 
the  open  mouth  of  an  animal  (Fig.  458  -  460).  This  variety  is  al- 
most universally  exhibited  by  the  corolla  of  the  Sage  or  Mint  family 
( which  is  therefore  called  Labiatte),  as  well  as  of  several  related 
families ;  and  the  calyx  is  frequently  bilabiate  also,  as  in  the  Sage. 
And  since,  in  the  corolla  of  these  families,  two  of  the  five  petals 
enter  into  the  composition  of  the  upper  lip,  and  three  into  that  of  the 
lower,  this  is  necessarily  inverted  in  the  bilabiate  calyx,  three  of  the 
sepals  combining  to  form  the  upper  lip,  and  two  to  form  the  lower. 

512.  "When  the  upper  lip  is  arched,  as  in  the  corolla  of  Lamium 
(Fig.  458),  it  is  sometimes  called  the  galea,  or  helmet.  "When  the 
two  lips  are  thus  gaping  and  the  throat  open,  the  corolla  is  said  to 
be  rinyent.  When  the  mouth  is  closed,  or  partly  so,  by  an  elevated 
portion  or  protuberance  of  the  lower  lip,  called  the  palate,  as  in  the 
Snapdragon  and  Toadflax  (Fig.  459,  460),  the  corolla  is  said  to  be 
personate,  or  masked. 

513.  In  the  Snapdragon,  the  base  of  the  corolla  is  somewhat  pro- 
tuberant, or  saccate,  on  the  anterior  side  ;  in  the  Toadflax,  the  pro- 
tuberance is  extended  into  a  hollow  spur.  A  projection  of  this  kind 
is  not  uncommon,  in  various  families  of  plants.  One  petal  of  the 
Violet  is  thus  spurred  or  calcarate  (Fig.  397) ;  so  is  one  of  the  outer 
petals  in  the  Fumitory,  and  each  of  them  in  Dicentra  (Fig.  370).  So, 
also,  one  of  the  sepals  is  spurred  or  strongly  sac-shaped  in  the  Jewel- 
weed  (Impatiens),  and  the  Larkspur  (Fig.  398)  ;  and  all  five  petals 
take  this  shape  in  the  Columbine.  A  monster  of  the  Toadflax  is 
occasionally  found,  in  which  the  four  remaining  petals  of  the  five 
which  enter  into  its  composition,  affect  the  same  irregularity,  and  so 
bring  back  the  flower  to  a  singular  abnormal  state  of  regularity. 
This  was  called  by  Linnajus  Peloria  ;  a  name  which  is  now  used  to 
designate  the  same  sort  of  monstrosity  in  different  flowers. 


THE    STAMKNS.  279 

514.  The  petals  are  sometimes  furnished  with  appendages  on 
their  inner  surface,  such  as  the  crown  at  the  summit  of  the  claw  in 
Silene  (Fig.  378,  449),  and  the  scales  similarly  situated  on  the 
gamopetalous  corolla  of  the  Comfrey,  &c.  These  appendages  some- 
times represent  a  circle  of  sterile  and  metamorphosed  stamens  ;  but 
more  commonly  they  seem  really  to  belong  to  the  petal. 

515.  As  to  duration,  sometimes  the  floral  envelopes  are  caducous, 
i.  e.  falling  off  when  the  blossom  opens,  as  the  calyx  in  the  Poppy  fam- 
ily and  the  corolla  of  the  Grape- Vine  (Fig.  384).  More  commonly 
they  are  deciduous,  or  fall  after  expansion,  but  before  the  fruit  forms. 
When  they  remain  until  the  fruit  is  formed  or  matured,  they  are 
persistent,  which  is  often  the  case  with  the  calyx,  especially  when 
it  has  a  green  color  and  foliaceous  texture.  When  they  persist  in  a 
dry  or  withering  state,  as  the  corolla  of  Heaths,  Campanula,  &c, 
they  are  said  to  be  marcescent. 

516.  Besides  serving  as  organs  of  protection,  the  sepals,  when 
green,  assimilate  sap,  and  act  upon  the  air  like  ordinary  foliage  (344, 
345).  The  petals,  like  other  uncolored  (that  is  greenless)  parts,  do 
not  evolve  oxygen,  but  abstract  it  from  the  air,  and  give  off  carbonic 
acid  ;  in  other  words,  they  decompose  assimilated  matter,  —  a  pro- 
cess which  appears  to  be  needful  in  flowering,  and  to  subserve  some 
important  end  at  the  time  (3G8-373).  The  tissue  of  a  petal  is 
much  the  same  as  that  of  a  leaf,  except  that  it  is  much  more  delicate 
and  the  fibre-vascular  system  is  generally  reduced  to  slender  bundles 
of  a  few  spiral  vessels,  &c,  which  form  its  veins. 


Sect.  VI.    The  Stamens. 

517.  The  Stamens  have  already  been  considered  in  a  general  way 
(418).  Before  describing  their  structure  more  particularly,  the 
principal  terms  which  relate  to  their  number,  connection,  and  posi- 
tion may  be  mentioned.  Most  of  these  terms  were  devised  by  Lin- 
naeus as  names  of  the  classes  of  his  Ai-tificial  System  of  classification 
(Part  II.  Chap.  IV.),  founded  mainly  upon  characters  furnished  by 
the  stamens.  Their  number  in  a  flower  is  accordingly  expressed 
by  the  names  of  the  eleven  or  twelve  earlier  Linnaean  classes  (990), 
put  into  adjective  form.  Thus,  a  flower  with  one  stamen  is  said  to 
be  monandrous  ;  with  two,  diandrous  ;  with  three,  trimidrous  ;  with 
four,  tetrandrous  ;  with  five,  pentandrous  ;  with  six,  hexandrous  ; 


280 


THE    FLOWER. 


with  seven,  heptandrous  ;  with  eight,  octandrous  ;  with  nine,  ennean- 
drous  ;  with  ten,  decandrous  ;  with  twelve,  dodecandrous.  When 
more  than  twelve,  and  inserted  on  the  calyx,  they  are  isocandrous,  or 
when  inserted  on  the  receptacle,  polyandrous. 

518.  As  to  their  union  with  each  other,  this  may  take  place  in 
various  ways.  Sometimes  the  filaments  are  combined,  while  the 
anthers  are  distinct.  When  thus  united  by  their  filaments  into  one 
set,  they  are  said  to  be  monadelphous  ;  as  in  the  Lupine,  &c.  (Fig. 

462)  and  Mallow. 
When  united  by  their 
filaments  into  two 
sets,  they  ai'e  diadel- 
phous,  as  in  most 
plants  of  the  Pulse 
family,  where  nine 
stamens  form  one  set 
and  the  tenth  is  soli- 
tary (Fig.  461);  and 
in  Dicentra  (Fig.  369  -  371),  where  the  six  stamens  are  equally  com- 
bined in  two  sets.  When  united  or  ar- 
ranged in  three  sets  or  parcels,  they  are 
said  to  be  triadelphous,  as  in  the  com- 
mon St.  Johnswort ;  or  if  in  several, 
polyadelphous ;  as  in  Linden.  When 
stamens  are  united  by  their  anthers  into 
a  tube  or  ring,  they  are  said  to  be  syn- 
genesious (Fig.  463,  464).  This  occurs 
in  the  Avhole  vast  order  of  Composite. 
Here  the  five  filaments  are  distinct ; 
whereas  in  Lobelia,  and  also  in  the 
Melon  and  Gourd  (Fig.  465,  466),  both 
the  filaments  and  the  anthers  are  united ;  that  is,  the  stamens  are 
monadelphous  as  well  as  syngenesious. 

519.  As  to  insertion,  stamens  are  hypogynous  (466)  when  borne 
on   the  receptacle,  that  is,  when  not  adnate  to   any  other  organ ; 


FIG.  461.  Diadelphous  stamens  (9  and  1)  of  a  Pea.  462.  Monadelphous  stamens  of  a 
Lupine. 

FIG.  463.     Five  syngenesious  stamens  of  a  Composita.     464.     The  same,  laid  open. 

FIG.  465.  Column  of  stamens,  at  once  triadelphous  and  syngenesious,  of  the  Gourd :  the 
floral  envelopes  cut  away.  466.  A  cross-section  of  the  united  anthers,  nearly  the  natural  size. 
467.  A  sinuous  anther  of  the  Melon. 


THE    STAMENS.  281 

perigynoits  (4G7)  when  borne  on  or  adnate  to  any  part  of  the  calyx ; 
epipetalous,  when  borne  on  the  corolla,  as  in  the  greater  number  of 
monopetalous  flowers ;  and  epigynous  (469), 
when  borne  on  the  ovary.  In  some  cases  the 
adnation  proceeds  further,  and  the  stamens  are 
inserted  on,  i.  e.  are  consolidated  with,  the 
style,  as  in  the  Orchis  family ;  then  they  are 
said  to  be  gynandrous  (Fig.  4G8). 

520.  There  are  two  cases  in  which  inequal- 
ity in  the  length  of  the  filaments  is  expressed  by 
a  technical  term.     Namely,  the  stamens   are 
said  to  be  didynamous  when,  being  only  four 
in  number,  they  are  in  pairs,  and  one  pair  is  468 
longer  than  the  other ;  as  in  Gerardia  (Fig.  407),  and  in  most  flowers 
with  a  bilabiate  corolla^p^nd  they  are  tetradynamous  when,  being 
six  in  number,  two  are  shorter  than  the  remaining  four,  as  in  Mus- 
tard and  all  that  family  of  plants  with  Cruciferous  flowers  (Fig.  406). 

521.  A  stamen  consists  of  its  filament  and  its  anther  (418). 
The  filament,  being  a  mere  stalk  or  support  of  the  anther,  is  not  an 
essential  part ;  it  is  to  the  anther  what  the  petiole  is  to  the  blade  of 
a  leaf.  Sometimes,  therefore,  it  is  wanting,  when  the  anther  is 
sessile.  The  anther  is  essential  to  a  perfect  stamen.  But  sometimes 
a  stamen,  or  what  stands  in  the  place  of  one,  is  destitute  of  an  anther, 
i.  e.  is  sterile,  as  in  Fig.  408  ;  and  also  the  upper  one  in  Fig.  468, 
st,  which  is  a  sterile  filament  enlarged  into  a  petal-like  body.  The 
true  nature  of  the  organ  is  known  by  its  position. 

522.  Tlie  Filament,  although  usually  slender  and  stalk-like,  assumes 
a  great  variety  of  forms  :  it  is  sometimes  dilated  so  as  to  resemble  a 
petal,  except  by  its  bearing  an  anther ;  as  in  the  transition  states  be- 
tween the  true  petals  and  stamens  of  the  Water-Lily  (Fig.  344).  The 
filament  is  anatomically  composed  of  a  central  bundle  of  spiral  ves- 
sels or  ducts,  which  represent  the  fibro-vascular  system  of  the  leaf, 
in  the  same  state  as  in  the  petiole,  enveloped  by  parenchyma ;  the 
outer  stratum  of  which  forms  a  delicate  epidermis. 

523.  The  Anther,  which  is  the  essential  part  of  the  stamen,  is  usu- 
ally borne  on  the  apex  of  the  filament ;  and  commonly  consists  of 
two  lobes,  or  cells  (thecce),  placed  side  by  side,  and  connected  by  a 
prolongation  of  the  filament,  called  the  connectivum,  or  connective. 

FIG.  468.     Stamens  and  style  of  a  Cypripedium,  united  into  one  body  or  column:  a,  a, 
anthers :  st.  a  sterile  stamen  :  stig.  the  stigma. 

24* 


282 


THE    FLOWER. 


524.  The  attachment  of  the  anther  to  the  filament  presents  three 
principal  modes.  1st.  When  the  base  of  the  connective  exactly 
corresponds  with  the  apex  of  the  filament  and  with  the  axis  of  the 
anther,  the  latter  is  termed  innate,  and  rests  firmly  upon  the  summit 

of  the  filament,  as  in  Fig.  469.  2d. 
When  the  lobes  of  the  anther  adhere 
for  their  whole  length  to  a  prolonga- 
tion of  the  filament,  or  to  a  broad 
connective  (whichever  it  be  called), 
so  as  to  appear  lateral,  it  is  said  to 
be  adnate ;  as  in  Magnolia,  Lirio- 
dendron  (Fig.  470),  &c.  Here  the 
anther  must  be  either  extrorse  or  in- 
trorse.  It  is  introrse,  or  tuiiied  in- 
4=9       4rj  in  wards,  when   it  occupies    the  inner 

side  of  the  connective,  and  faces  the  pistils,  as  in  Magnolia ;  but 
when  the  anther  looks  away  from  the  pistils  and  towards  the  petals 
or  sepals,  it  is  said  to  be  extrorse,  or  turned  outwards,  as  in  Iris, 
Liriodendron,  and  Asarum  (Fig.  472).  3d.  When  the  anther  is 
fixed  by  a  point  near  its  middle  to  the  apex  of  the  filament,  on  which 
it  lightly  swings,  it  is  said  to  be  versatile  ;  as  in  all  Grasses,  in  the 
Lily,  and  in  the  Evening  Primrose  (Fig.  471),  &c.  In  this  case,  as 
in  the  preceding,  the  anther  is  said  to  be  introrse,  or  incumbent, 
when  it  is  turned  towards  the  pistil,  which  is  the  most  common 
way  ;  and  extrorse,  when  it  faces  outwards. 

525.  The  connective  is  often  inconspicuous  or  wholly  wanting,  so 
that  the  lobes  of  the  anther  are  directly  in  contact  on  the 

apex  of  the  filament ;  but  it  is  commonly  evident.  It  is 
often  produced  into  an  appendage  at  the  tip  of  the  anther, 
as  in  Magnolia  and  Liriodendron  (Fig.  470),  the  Papaw 
(Fig.  956,  where  it  forms  a  rounded  top),  and  Asarum 
(Fig.  472).  Appendages  or  processes  from  the  back  of 
the  connective  are  seen  in  the  stamens  of  the  Violet  and  of 
many  Ericaceous  plants.  i:i 

526.  Each  of  the  two  cells  or  lobes  of  the  anther  is  marked  with 
a  lateral  line  or  furrow,  running  from  top   to  bottom ;  this  is  the 


FIG.  469.  A  stamen  of  Isopyrum  biternatum,  with  an  innate  anther  470.  Stamen  of  Lirio- 
dendron, or  Tulip-tree,  -with  an  adnate  extrorse  anther.  471.  Stamen  of  (Enothera  glauca, 
with  the  anther  fixed  by  its  middle  and  versatile. 

FIG.  472.   A  stamen  of  Asarum  Canadense,  with  an  adnate  anther. 


THE    ANTHER. 


2S3 


suture,  or  line  of  dehiscence,  by  which  the  anther  opens  at  maturity 
to  discharge  the  pollen  (Fig.  473).  This  line  is  for  the  most  part 
exactly  lateral  in  innate  anthers  ;  hut  it  looks  more  or  less  evidently, 
and  often  directly,  inward  in  introrse,  and  outward  in  extrorse 
anthers.  In  certain  cases  the  cells  of  the  anther  open  only  at  the 
summit,  by  a  pore  or  hole,  as  in  Py- 
rola  (Fig.  474)  and  most  Fricaceous 
plants.  In  the  Whortleberry  family 
each  cell  or  lobe  is  commonly  pro- 
longed into  a  tube,  which  opens  only 
at  the  apex  ( Fig.  391).  In  the  Bar- 
berry (Fig.  475),  and  in  nearly  all 
plants  of  the  Barberry  family,  the 
whole  face  of  each  anther-cell  sepa- 
rates by  a  continuous  line,  forming  a  kind  of  door,  which  is  attached 
at  the  top,  and  turns  back,  as  if  on  a  hinge :  in  this  case  the  anthers 
are  said  to  open  by  valves.  In  the  Sassafras  (Fig.  1114),  and  many 
other  plants  of  the  Laurel  family,  each  lobe  of  the  anther  opens  by 
two  such  valves,  like  trap-doors. 

527.  Sometimes  the  anthers  are  one-celled  by  the  suppression  of 

one  lobe,  being  dimidiate,  or  reduced  as  it  were  to  half-stamens,  as 

in  Gomphrenaor  Globe-Amaranth  (Fig.  478). 

But  most  one-celled  anthers  are  the  result  of 

the  confluence  of  the  two  cells  into  one.     A 

comparison  of  the  two-celled  anther  of  Pent- 

stemon  pubescens,  where  the  two  cells  diverge 

below   and  are   somewhat  united  at  the  top 

(Fig.  47  G)  with  the  kidney-shaped  one-celled 

anther  of  a  Mallow,  opening  by  a  continuous 

line  all  round  the  margin  (Fig.   477),  shows 

how  this  result  is  brought  about. 

As   to   anatomical    structure,   each   lobe   of  the    full-grown 

anther   consists   of  an  epidermal  membrane,  lined  with  a  delicate 

fibrous  tissue,  and  surrounding  a  cavity  filled  with  pollen.     This 


528. 


FIG.  473.  A  stamen,  with  its  anther,  b,  opening  in  the  normal  manner  down  the  whole 

length  of  the  outer  side  of  each  cell :  a,  the  filament. 

FIG.  474.  Stamen  of  a  Pyrola ;  each  cell  of  the  anther  opening  by  a  terminal  orifice. 

FIG.  475.  Stamen  of  a  Barberry  ;  the  cells  of  the  anther  opening  by  an  uplifted  valve. 

FIG.  476.  A  stamen  of  Pentstemon  pubescens  ;  anther-cells  slightly  confluent. 

FIG.  477.  Stamen  of  Mallow  ;  the  two  cells  confluent  into  one,  opening  round  the  margin. 

FIG.  478.  Anther  of  Globe  Amaranth,  of  only  one  cell ;  the  other  cell  obliterated. 


284 


THE    FLOWER. 


fibrous  lining  (a  little  of  which  is  shown  in  Fig.  45,  from  the  anther 
of  Cobrea)  is  composed  of  simple  or  branching  threads  or  bands, 
which  formed  the  thickening  deposit  on  the  walls  of  large  paren- 
chymatous cells ;  all  the  membrane  between  the  bands  becoming  ob- 
literated as  the  anther  approaches  maturity,  the  latter  alone  remain, 
as  a  set  of  delicate  fibres.  This  fibrous  layer  gradually  diminishes 
in  thickness  as  it  approaches  the  line  of  dehiscence  of  the  cell, 
and  there  it  is  completely  interrupted.  These  very  elastic  and  hygro- 
metric  threads  lengthen  or  contract  in  different  ways,  according 
as  the  anther  is  dry  or  moist,  and  are  thought  to  favor  the  egress 
of  the  pollen.  The  outer  stratum  of  the  wall  of  the  anther  in  dry- 
ing contracts  more  than  the  inner,  and  so  opens  the  cell,  in  many 
cases  turning  the  walls  inside  out  after  dehiscence,  as  in  Lilies 
and  Grasses. 

529.  Of  all  the  floral  organs,  the  anther  shows  least  likeness  to 
a  leaf.  Nevertheless,  the  early  development  is  nearly  the  same. 
Like  the  leaf,  the  apex  is  earliest  formed,  appearing  first  as  a  solid 
protuberance,  and  the  anther  is  completed  before  the  filament,  which 
answers  to  the  leafstalk,  makes  its  appearance.  At  first,  the  anther 
is  of  a  greenish  hue,  although  at  maturity  the  cells  assume  a  differ- 
ent color,  more  commonly  yellow.  A  transverse  section  of  the  form- 
ing anther  shows  four  places  in  which  the  transformation  of  the  paren- 
chyma into  pollen  commences,  which  answer  to  the  centre  of  the 
four  divisions  of  the  parenchyma  of  a  leaf,  viz.  the  two  sides  of  the 
blade,  each  distinguished  into  its  upper  and  its  lower  stratum.     So 

that  the  anther  is  primarily  and  typically  four-celled  ; 
each  lobe  being  divided  by  a  portion  of  untransformed 
tissue,  stretching  from  the  connective  to  the  opposite 
side,  which  corresponds  to  the  margin  of  the  leaf  and 
the  line  of  dehiscence.  This  appearance  is  presented 
by  a  large  number  of  full-grown  anthers :  but  the  par- 
tition usually  disappears  before  the  anther  opens,  when 
each  lobe  becomes  single  celled.  The  normal  anther 
is  consequently  considered  as  two-celled.  In  Meni- 
spermum  and  Cocculus,  however,  the  anther  is  strongly 
four-lobed  externally,  and  each  lobe  forms  a  distinct 
479  cell  at  maturity. 

530.  Viewed  morphologically,  therefore,  the  filament  answers  to 

FIG.  479.  Plan  of  a  stamen  as  answering  to  a  leaf;  the  upper  part  of  the  anther  cut  away, 
and  the  summit  of  a  leaf  represented  above  it. 


THE    POLLEN. 


285 


the  petiole  of  a  leaf;  the  anther,  to  the  blade.  The  connective 
represents  the  midrib ;  the  lobes  or  cells  of  the  anther  represent  the 
two  symmetrical  halves  of  the  blade  ;  and  the  line  of  dehiscence  is 
normally  along  the  margins  of  the  transformed  leaf.  What  in  the 
leaf  would  be  cells  of  parenchyma  develop  as 

531.  Pollen.  This  usually  powdery  substance  consists  of  grains, 
of  definite  size  and  shape,  uniform  in  the  same  plant,  but  often  very 
different  in  different  species  or  families.  The  grains  are  commonly 
single  cells,  globular  or  oval  in  shape,  and  of  a  yellow  color.  But 
in  Spiderwort  they  are  oblong ;  in  the  Cichory  and  Thistle  tribes 
many-sided  (Fig.  485)  ;  in  the  Musk-plant  spirally  grooved  (Fig. 
480)  ;  in  the  Mallow  family  (Fig.  483)  and  the  Squash  and  Pump- 


kin, beset  with  bristly  projections,  &c.  The  pollen  .of  Pine  (Fig. 
486),  as  well  as  that  of  the  Onagracerc  (Fig.  487,  489),  is  not  so 
simple,  but  appears  to  consist  of  three  or  four  blended  cells  ;  that  of 
all  true  Ericacere  evidently  consists  of  four  grains  or  cells  united 


(Fig.  488).     The   most  extraordinary  shape  is  that  of  Zostera,  or 
the  Eel-grass  of  salt-water,  in  which  the  grains 
(destitute  of  the  outer  coat)  consist  of  long  and 
slender  threads,  which,  as  they  lie  side  by  side 
in  the  anthei-,  resemble  a  skein  of  silk. 

532.  Pollen-grains  are  usually  formed  in  fours, 
by  the  division  of  the  living  contents  of  mother 
cells  first  into  two,  and  these  again  into  two  parts,  which,  acquiring 
a  coat  of  cellulose,  become  specialized  cells  (36).  As  the  pollen 
completes  its  growth,  the  walls  of  the  mother  cells  are  usually  oblit- 
erated.    But  sometimes  the  enclosing  cells  persist,  and  collect  the 


FIG.  480-489.  Forms  of  pollen :  4S0,  from  Mimulus  mosehatus  :  481,  Sicyos:  482,  Echi- 
nocystis :  483,  Hibiscus  :  4S4,  Lily  :  485,  Cichory :  4S6,  Pine :  48",  Circasa  :  4SS,  Kalmia  : 
489,  Evening  Primrose. 


286  THE    FLOWER. 

pollen-grains  into  coherent  masses  of  various  consistence,  as  is  re- 
markably the  case  in  the  Orchis  and  Milkweed  families  (Fig.  543, 
&c).     Such  pollen-masses  are  sometimes  termed  pollinia. 

533.  The  threads,  resembling  cobweb,  that  are  loosely  mixed  with 
the  pollen  of  the  Evening  Primrose,  are  the  vestiges  of  obliterated 
mother  cells. 

534.  Pollen-grains  have  two  coats.  The  outer  coat,  called  the 
extine,  is  comparatively  thick,  and  often  granular  or  fleshy.  This  is 
later  formed  than  the  inner,  and  by  a  kind  of  secretion  from  it :  to  it 
all  the  markings  belong.  The  inner  coat,  or  intine,  which  is  the 
proper  cell-membrane,  is  a  very  thin  and  delicate,  transparent  and 
colorless  membrane,  of  considerable  strength  for  its  thickness.  The 
pollen  of  Zostera  and  of  some  other  aquatic  plants  is  destitute  of  the 
outer  coat  (531). 

535.  The  cavity  enclosed  by  the  coats  is  filled  with  a  viscid  liquid, 
rich  in  protoplasm,  Avhich  often  appears  slightly  turbid  under  the 
higher  powers  of  ordinary  microscopes,  and,  when  submitted  to  a 
magnifying  power  of  about  three  hundred  diameters,  is  found  to 
contain  a  multitude  of  minute  particles  (fovillce),  the  larger  of 
which  are  from  the  four-thousandth  to  the  five-thousandth  of  an  inch 
in  length,  and  the  smaller  only  one  fourth  or  one  sixth  of  this  size. 
The  smaller  exhibit  the  constant  molecular  motion  of  all  such  mi- 
nute particles  when  suspended  in  a  liquid  and  viewed  under  suffi- 
cient magnifying  power.  When  wetted,  the  grains  of  pollen  prompt- 
ly absorb  water  by  endosmosis  (37),  and  are  distended,  changing 
their  shape  somewhat,  and  obliterating  the  longitudinal  folds,  one  or 
more  in  number,  which  many  grains  exhibit  in  the  dry  state.  Soon 
the  more  extensible  and  elastic  inner  coat  inclines  to  force  its  Avay 
through  the  Aveaker  parts  of  the  outer,  especially  at  one  or  more 
thin  points  or  pores  ;  sometimes  forming  a  projection  of  considerable 
length,  when  the  absorption  is  slow  and  the  exterior  coating  tough. 
If  the  absorption  continues,  the  distention  soon  overcomes  the  resist- 
ance of  the  elastic  inner  coat,  which  bursts,  and  the  contents  are  dis- 
charged. 

536.  When  fresh,  living  pollen  falls  upon  the  stigma,  however, 
which  is  barely  moist,  it  does  not  burst,  but  the  inner  membrane  is 
slowly  projected,  often  through  particular  points,  clefts,  or  openings 
of  the  outer  coat,  in  the  form  of  an  attenuated  transparent  tube  (Fig. 
537-547),  filled  with  its  fluid  contents,  and  which  penetrates  the 
naked  and  loose  cellular  tissue  of  the  stigma,  and  buries  itself  in 


THE    PISTILS.  287 

the  style.  This  is  not  a  mechanical  protrusion,  but  a  true  growth, 
the  materials  for  which  are  supplied  by  nourishment  imbibed  from 
the  stigma  and  style.  Its  further  course  and  the  office  it  subserves 
will  be  considered  after  the  structure  of  the  pistil  is  made  known. 
(Sect.  IX.) 

Sect.  VII.    The  Pistils. 

537.  The  Pistils  (419)  occupy  the  centre  of  the  flower,  and  ter- 
minate the  axis  of  growth.  Linnaeus  established  the  orders  of  his 
Artificial  System  mainly  upon  the  pistils,  and  this  introduced  a  se- 
ries of  terms  expressive  of  their  number  in  a  flower,  analogous  to 
those  used  for  the  number  of  stamens  (517).  Thus  a  flower  with  a 
single  pistil  is  said  to  be  monogynous  ;  with  two,  digynous  ;  with  three, 
trigynous  ;  with  four,  tetragynous  ;  with  five,  pentagynous  ;  and  so 
on  :  when  more  numerous  or  indefinite,  the  flower  is  polygynous. 

538.  It  is  comparatively  seldom  that  the  pistils  are  exactly  equal 
to  the  petals  or  sepals  in  number ;  they  are  sometimes  more  numer- 
ous, and  arranged  in  several  rows  upon  the  enlarged  or  prolonged 
receptacle,  as  in  the  Magnolia,  the  Strawberry,  &c,  and  perhaps 
more  frequently  they  are  reduced  to  less  than  the  symmetrical  num- 
ber, or  to  a  single  one.  Yet  often  what  appears  to  be  a  single  pistil 
is  not  so  in  reality,  but  a  compound  organ,  formed  by  the  union  of 
two,  three,  or  a  greater  number  of  simple  pistils  ;  these  organs  being 
subject  to  coalescence  in  the  same  way  as  the  stamens  (518)  and  the 
petals  (507,  462). 

539.  A  simple  and  complete  pistil,  as  already  described  (420),  is 
composed  of  three  parts :  the  Ovary,  or  seed-bearing  portion ;  the 
Style,  or  tapering  portion,  into  which  the  apex  of  the  ovary  is  pro- 
longed ;  and  the  Stigjia,  usually  situated  at  the  summit  of  the  style, 
consisting  of  a  part,  or  sometimes  a  mere  point,  of  the  latter,  divested 
of  epidermis,  with  its  moist  cellular  tissue  exposed  to  the  air.  The 
ovary,  which  contains  the  ovules,  or  bodies  which  are  to  become 
seeds,  is  of  course  a  necessary  part  of  the  pistil ;  the  stigma,  which 
receives  from  the  anthers  the  pollen  (531)  by  which  the  ovules  are 
fertilized,  is  no  less  necessary  ;  but  the  intervening  style  is  no  more 
essential  to  the  pistil  than  the  filament  is  to  the  stamen,  and  is  there- 
fore not  uncommonly  wanting.  In  the  latter  case,  the  stigma  is 
sessile  upon  the  apex  of  the  ovary.  In  Tasmannia  it  actually  occu- 
pies the  side  of  the  ovary  for  nearly  its  whole  length,  and  is  sepa- 


2«3  THE    FLOWER. 

rated  from  the  line  to  which  the  ovules  are  attached  only  by  the 
thickness  of  the  walls :  it  is  nearly  the  same  in  our  Schizandra 
(Fig.  493),  another  plant  of  the  Magnolia  family.  The  style  some- 
times proceeds  from  the  side,  or  even  from  near  the  apparent  base 
of  the  ovary  ;  as  in  the  Strawberry  (Fig.  428). 

540.  When  the  pistil  is  single,  or  when  several  coalesce  into  one,  it 
will  necessarily  terminate  the  axis,  and  appear  to  be  a  direct  con- 
tinuation of  it.  When  there  are  two  pistils  in  the  flower,  they  al- 
ways stand  opposite  each  other  (so  that  if  they  coalesce  it  is  by 
their  inner  faces)  ;  and  are  either  lateral  as  respects  the  flower,  that 
is,  one  on  the  right  side  and  the  other  on  the  left,  in  a  plane  at  right 
angles  to  the  bract  and  axis  (444),  as  in  the  Mustard  family,  the 
Gentian  family,  and  a  few  others  ;  or,  more  commonly,  anterior  and 
posterior,  one  before  the  axis  and  the  other  before  the  bract  of  the 
axillary  flower.  When  they  accord  in  number  with  the  sepals  or 
petals,  they  are  either  opposed  to  or  alternate  with  them;  and  the 
two  positions  in  this  respect  are  sometimes  found  in  nearly  related 
genera,  so  as  to  baffle  our  attempts  at  explaining  the  cause  of  the 
difference.  In  Pavonia,  for  example,  the  five  pistils  are  opposite 
the  petals  ;  in  Malvaviscus  and  Hibiscus,  alternate  with  them.  In 
Sida  (when  five)  they  stand  opposite  the  petals  ;  in  Abutilon,  opposite 
the  sepals. 

541.  Pistils  occur  under  such  a  diversity  of  forms,  and  exhibit 
such  various  complications,  that  the  plan  of  their  structure  and  the 
distinction  between  simple  and  compound  pistils  require  to  be  well 
understood.  Commencing,  therefore,  with  the  most  natural  forms, 
and  proceeding  gradually  to  the  more  complex  or  disguised,  we  first 
consider 

542.  The  Simple  Pistil,  and  the  way  in  which  it  answers  to  a  leaf. 
A  simple  pistil  answers  to  a  single  leaf.  A  compound  pistil  answers 
to  two  or  more  leaves  combined,  just  as  a  monopetalous  corolla 
answers  to  two  or  more  petals,  or  leaves  of  the  flower,  united  into 
one  body.  As  to  its  morphology,  the  botanist  regards  a  simple 
pistil  as  consisting  of  the  blade  of  a  leaf,  curved  inwards  until  its 
margins  meet  and  unite,  forming  in  this  way  a  closed  case,  or  pod, 
which  is  the  ovary.  So  that  the  upper  face  of  the  altered  leaf 
answers  to  the  inner  surface  of  the  ovary,  and  the  lower,  to  its 
outer  surface.  And  the  ovules  are  borne  on  what  answers  to  the 
united  edges  of  the  leaf.  The  tapering  summit,  rolled  together 
and  prolonged,  forms  the  style,  when  there  is  any ;  and  the  edges 


THE    SIMPLE    PISTIL. 


289 


of  the  altered  leaf  turned  outwards,  either  at  the  tip  or  along  the 
inner  side  of  the  style,  form  the  stigma.  This  will  be  clearly  un- 
derstood on  comparing  Fig.  342  and  Fig.  491,  which  are  pistils 
transversely  divided,  with  Fig.  490,  a  leaf  curved  inwards  until  its 
margins  nearly  meet,  and  with  Fig. 
492,  a  simple  pistil  of  Caltha  or 
Marsh-Marigold  which  has  matured, 
split  open  along  the  inner  side  to 
discharge  the  seeds  it  bore,  and 
spread  out  into  the  shape  of  a  leaf. 

543.  The  line  formed  by  the  union 
of  the  margins  of  the  leaf  is  called 
the  Inner  or  Ventral  Suture,  and 
always  looks  towards  the  axis  of  the 
flower.      This   is   a  true   suture,  or 

seam,  as  the  word  denotes.  The  opposite  line,  answering  to  the  mid- 
rib, is  sometimes  apparent  as  a  thickened  line,  and  is  termed  the 
Outer  or  Dorsal  Suture.  The  ovules  or  young  seeds  are  borne  (in 
all  ordinary  cases  at  least)  on  the  inner  suture,  or  some  part  of  it ; 
that  is,  on  what  answers  to  the  united  margins  of  the  infolded  and 
transformed  leaf.  The  part  in  the  cell  of  the  ovary  to  which  the 
ovules  are  attached,  and  which  is  commonly  more  or  less  enlarged 
or  projecting  when  the  ovules  are  numerous,  is  named 

544.  The  Placenta.     As  this  corresponds  with  the  ventral  suture, 
and  is  in  fact  a  part  of  it,  or  a  cellular  growth  from  it,  it  always 

belongs  next  the  axis  of  the  flower ; 
as  is  evidently  the  case  when  two, 
three,  or  more  pistils  are  present. 
Each  placenta  necessarily  consists  of 
two  parts,  one  belonging  to  each  margin 
of  the  transformed  leaf.  It  therefore  is 
frequently  two-lobed,  or  of  two  diverg- 
494  495  ing  lamellae  (Fig.  342).     This  shows 

why  the    ovules    are    apt   to   occupy  two  longitudinal  rows,  as  in 


FIG.  490.    A  leaf  infolded,  to  illustrate  the  theory  of  the  formation  of  the  pistil. 

FIG.  491.  Pistil  of  Isopyrum  biternatum,  cut  across  ;  the  inner  or  ovule-bearing  side 
turned  towards  the  observer. 

FIG.  492.     Ripe  pistil  of  Caltha  palustris,  after  opening  and  discharging  the  seeds. 

FIG.  493.  Vertical  section  of  a  pistil  of  Schizandra  coccinea ;  a  side  view.  494.  Tistil  of 
Hydrastis.  495.  Pistil  of  Actsea  rubra,  cut  across,  so  as  to  show  the  interior  of  the  ovary  (the 
ventral  suture  turned  towards  the  observer). 

25 


290  THE    FLOWER. 

the  figure  last  cited,  and  in  Fig.  491,  495,  &c,  one  row  belonging  to 
each  margin  of  the  leaf.  A  simple  pistil,  accordingly,  can  have 
only  one  placenta ;  but  that  is  structurally  double. 

545.  So  a  single  pistil  can  have  only  one  style  and  one  stigma. 
But  as  the  stigma  answers  to  the  margins  of  the  apex  of  the  leaf, 
this  must  also  be  double  in  its  nature.  And  this  is  evidently  the 
case  in  the  Peony  and  Isopyrum  (Fig.  491),  in  the  Tulip,  as  well 
as  in  Fig.  493  -  495,  and  in  almost  all  cases  in  which  the  stigma 
extends  down  the  inner  face  of  the  style,  as  it  frequently  does. 
Such  unilateral  stigmas  Ave  accordingly  take  to  be  the  typical  form ; 
and  say  that,  while  the  united  margins  of  the  transformed  leaf  which 
compose  the  ventral  suture  are  turned  inwards  into  the  cell  of  the 
ovary  to  bear  the  ovules,  in  the  simple  style  they  are  exposed  external- 
ly to  form  the  stigma.  Where  the  stigma  is  terminal,  or  occupies 
only  the  apex  of  the  style,  we  suppose  that  these  margins  are  in- 
folded in  the  style  also,  and  form  in  its  interior  the  loose  conducting 
tissue  through  which  a  communication  is  established  between  the 
stigma  and  the  interior  of  the  ovary. 

546.  The  ovary  of  a  simple  pistil  obviously  can  have  but  one 
cavity  or  cell ;  except  from  some  condition  out  of  the  natural  order 
of  things.  But  the  converse  does  not  hold  true  :  all  pistils  of  a  sin- 
gle cell  are  not  simple.  Many  compound  pistils  are  one-celled,  as 
will  presently  be  explained. 

547.  A  leaf  or  member  of  the  gynrecium  then,  when  separate, 
forms  a  simple  pistil ;  when  combined  with  others,  it  makes  part  of  a 
compound  pistil.  It  is  convenient  to  have  a  name  which  shall  desig- 
nate a  single  pistil-leaf,  whether  occurring  as  a  distinct  simple  pistil, 
or  as  an  element  of  a  compound  pistil.  For  this  purpose  the  name 
of  Caepel  has  been  devised.  A  carpel  is  either  a  simple  pistil, 
or  is  one  of  a  circle  of  leaves  which  compose  a  compound  pistil. 
When  the  pistils  are  distinct  from  each  other,  they  are  said  to  be 
apocarpous  ;  when  united  into  one  body,  syncarpous.  This  union 
produces  a 

548.  Compound  Pistil.  All  degrees  of  union  of  the  carpels  may 
be  observed,  from  the  coalescence  of  the  lower  part  of  their  ovaries, 
their  summits  remaining  separate  (as  in  Fig.  49  G),  or  from  the  com- 
plete union  of  the  ovaries  into  one  body,-the  styles  remaining  sepa- 
rate (as  in  Fig.  497),  to  the  complete  coalescence  of  the  styles  also 
(Fig.  498),  and  even  of  the  stigmas  (Fig.  499),  into  one  body.  It  is 
evidently  the  same  as  if  two  or  more  pistils  (in  Fig.  497  -  499,  three 


THE    COMPOUND    PISTIL. 


291 


pistils)  were  pressed  together  as  they  grew  and  consolidated  more  or 
less  completely  into  one.  And  in  this,  the  most  normal  case,  Ave  have 
as  the  result  compound  pistils 

549.  With  two  or  more  Cells  and  Axilc  Placenta.    For  it  is  evident 


that,  if  the  contiguous  parts  of  a  whorl  of  three  or  more  closed  car- 
pels cohere,  the  resulting  compound  ovary  will  have  as  many  cavi- 
ties, or  cells,  as  there  are  carpels  in  its  composition,  and  the  placentae 
(one  in  the  inner  angle  of  each  carpel)  will  all  he  brought  together 
in  the  axis  of  the  compound  pistil.  And  the  partitions,  or  Dissep- 
iments, which  divide  the  compound  ovary  into  cells,  manifestly 
consist  of  the  united  contiguous  portions  of  the 
walls  of  the  carpels.  These  necessarily  are 
composed  of  two  layers,  one  belonging  to  each 
carpel ;  and  in  ripe  pods  they  often  split  into 
the  two  layers.  True  dissepiments  must  always 
be  equal  in  number  to  the  carpels  of  which  the 
compound  pistil  is  composed. 

550.  In  certain  cases,  indeed,  there  are  addi-  50° 

tional  partitions,  or  false  dissepiments.     These  are  commonly  projec- 

FIG.  49C.  Pistil  of  a  Saxifrage,  composed  of  two  carpels  or  simple  pistils  united  below,  but 
distinct  above  ;  cut  across  both  above  and  below. 

FIG.  497.     Pistil  of  common  St.  Johnswort,  of  three  united  ovaries  ;  their  styles  distinct. 

FIG.  498.  The  same  of  another  species  of  St.  Johnswort  (Hypericum  prolificuin),  the  styles 
also  united  into  one,  which,  however,  split  apart  in  the  fruit. 

FIG.  499.  Pistil  of  Tradescantia  or  Spiderwort,  even  the  three  stigmas  united  into  one. 
The  ovary  in  all  cut  across  to  show  the  internal  structure. 

FIG.  500.  Cross-section  of  a  flower  of  Flax ;  each  of  the  five  cells  of  the  ovary  partly  divided 
by  an  imperfect  false  partition  from  the  back. 


292 


THE    FLOWER. 


DOo. 


tions  or  growths  from  the  dorsal  suture  ;  whether  in  a  simple  pistil  (as 
that  of  most  species  of  Astragalus,  Fig.  805),  or  from  the  back  of 
each  proper  cell  of  a  compound  pistil,  as  in  the  Service-berry,  the 
Blueberry,  and  the  common  Flax  (Fig.  500). 

551.  "We  have  considered  only  the  case  of  compound  pistils  of  two 
or  more  cells  in  the  ovary.  But  compound  pistils  also  not  unfre- 
quently  occur 

552.  Witll  Only  one  Cell.  And  of  these  there  are  two  kinds  to  be 
noticed,  those  with  axile,  and  those  with  parietal  jplacentce.  That  is, 
in  the  first,  the  ovules  are  borne  in  the  axis  or  centre  of  the  ovary, 
either  at  the  base  or  on  a  column  which  occupies  the  centre ;  in  the 
second,  they  are  borne  on  some  part  of  the  parietes  or  walls  of  the 
ovary.     The  first,  viz. 

With  a  Free  Central  Placenta,  is  found  in  the  Primrose,  Purslane 
(Fig.  889),  and  Pink  families  (Fig.  432,  501,  502). 
In  the  Pink  family  this  evidently  results  from  the  ob- 
literation of  the  dissepiments  (as  many  as  there  are 
styles  or  stigmas)  ;  and  vestiges  of  these  may  be  de- 
tected at  an  early  stage,  and  sometimes  at  the  base  of 
the  full-grown  ovary ;  while  certain  plants  of  the  same 
family,  of  otherwise  identical  structure,  retain  the  par- 
titions even  in  the  ripe  pod.  In  other  instances,  as  in 
Diona^a,  Thrift,  &c,  this  is  doubtless  a  modification  of 
parietal  placentation,  with  ovules  produced  only  at  the 
bottom.  This  brings  us  to  the  case  of  compound  one- 
celled  pistils 

554.  With  Parietal  PlaceiltBB,  that  is,  with  the  placenta?  borne  on 
the  sides  or  parie- 
tes of  the  ovary, 
as  in  the  Poppy, 
Caper,  Cistus  or 
Rock-Rose  (Fig. 
507),  Violet,  Sun- 
dew (Fig.  510), 
and  Currant  families,  and  many  others 


To  comprehend  this  per- 


FIG.  501.  Vertical  section  through  the  compound  tricarpellary  ovary  of  a  plant  of  Spergu- 
laria  rubra,  showing  the  free  central  placenta.    502.  Transverse  section  of  the  same. 

FIG.  503-505.  Diagrams  illustrating  parietal  and  free  central  placentation.  503.  Cross- 
section  of  a  tricarpellary  ovary,  with  a  free  central  placenta,  produced  by  the  obliteration  of 
the  dissepiments.  501.  Section  of  an  ovary  with  three  strictly  parietal  placentae.  505.  Same, 
except  that  there  are  incomplete  partitions. 


THE    COMPOUND    PISTIL. 


293 


fectly,  we  have  only  to  imagine  two,  three,  or  any  number  of  pistil- 
leaves  (like  Fig.  490),  arranged  in  a  circle,  to  unite  Avith  one  another 
by  their  contiguous  edges,  either  without  any  intro- 
flexion  or  infolding  at  all  (Fig.  504),  or  at  least 
without  their  infolded  edges  having  reached  the  cen- 
tre and  united  there  (Fig.  505,  506).  The  combina- 
tion is  accordingly  much  like  that  by  which  petals 
unite  to  form  a  monopetalous  corolla,  only  the  edges 
of  the  pistil-leaves  are  always  turned  in,  Avhere  they 
bear  the  ovules.  Such  an  ovary  may 
well  be  compared  Avith  the  valvate  un- 
opened calyx  of  Clematis,  the  margins 
of  the  sepals  more  or  less  turned  in- 
wards (Fig.  445).  Every  gradation  is 
found  between  axile  and  parietal  pla- 
507  centation,  especially  in  the  St.  Johns-  506 

wort  family  (Fig.  508,  509)  and  in  the  Gourd  family. 

555.  An  ovary  with  parietal  placentae  is  necessarily  one-celled; 
except  it  be  divided  by  an  anomalous  partition,  such  as  is  found  in 

Cruciferous  plants,  and  in  the  Trum- 
pet Creeper. 

556.  It  Avill  be  seen  that   parietal 
placenta)  are  necessarily  double,  like 
the  placenta  of  a  simple  ovary,  or  of 
each  carpel  of  a  compound  several- 
celled  ovary  ;  but  Avith  this  difference, 
that  in  these  the  two  portions  belong  to  the  two  margins  of  the 
same  carpel ;  Avhile  in  parietal  placentae  they  are  formed  from  the 
coalescent  margins  of  two  adjacent  carpels. 

557.  The  number  of  carpels  of  which  a  compound  ovaiy  consists 
is  indicated  by  the  number  of  true  dissepiments  when  these  exist ; 
or  by  the  number  of  placenta?,  when  these  are  parietal ;  or  by  the 
number  of  styles  or  stigmas,  when  these  are  not  Avholly  united  into 
one  body.     Thus  a  simple  pistil  has  a  single  cell,  a  single  placenta, 


FIG.  506.  Plan  of  a  one-celled  ovary  with  three  parietal  placentae,  cut  across  below  ;  the 
upper  part  showing  the  top  of  the  three  leaves  it  is  composed  of,  approaching,  but  not  united. 

FIG.  507.  Ovary  of  Ilelianthemum  Canadense,  cut  across,  showing  the  ovules  on  three 
parietal  placenta;. 

FIG.  50S.  Transverse  section  of  the  ovary  of  Hypericum  graveolens ;  the  three  large 
placentas  meeting  in  the  centre,  but  not  cohering.  509.  Similar  section  of  a  ripe  pod  of  the 
same  ;  the  placentas  now  evidently  parietal. 

25* 


294  THE    FLOWER. 

and  a  single  style.     A  pistil  of  two  carpels  may  be  two-celled,  with 
two  placentae,  two  styles,  or  two  stigmas,  &c* 

*  There  are,  however,  some  exceptions  which  qualify  these  statements  :  — 

1.  Each  placenta  being  a  double  organ  (556),  it  occasionally  happens  that 
the  two  portions  are  separated  more  or  less,  as  in  Orobanchaceous  plants,  where 
a  dicarpellary  ovary  appears  on  this  account  to  have  four  parietal  placenta; ; 
either  approximate  in  pairs  (as  in  our  Cancer-root,  Conopholis),  or  equidis- 
tant (as  in  Aphyllon). 

2.  Analogous  to  this  is  the  case  where  the  two  constituent  elements  of  the 
stigma  (the  only  essential  part  of  the  style)  separate  into  two  half-stigmas,  as  is 
partially  seen  in  Fig.  494,  495.     The  stigma,  no  less  than  the  placenta,  belongs 

to  the  margins  of  the  infolded  leaf  (545),  these  margins  being 
ovuliferous  in  the  ovary  and  stigmatiferous  in  the  style  ;  as  Mr. 
Brown,  the  most  profound  botanist  of  this  or  any  age,  has 
clearly  shown.  These  two  constituent  portions  of  the  style  or 
stigma  occasionally  separate,  cither  entirely  or  in  part,  as  in 
Euphorbiaceous  plants,  in  Grasses,  and  especially  in  Drosera 
(Fig.  510),  where  there  are  consequently  twice  as  many  nearly 
distinct  styles  as  there  are  parietal  placenta;  in  the  compound 
ovary  If  the  two  component  parts  of  the  style  of  each  carpel 
were  reunited  into  one,  in  the  usual  manner,  their  number 
<N.    /■/■  would  equal  the  placenta;,  and  their  position  would  be  alter- 

\    '  nate  with  the  latter.     But  since,  in  parietal  placentation,  each 

half-placenta  is  confluent  (not  with  its  fellow  of  the  same 
carpel,  but)  with  the  contiguous  half-placenta  of  the  adjacent  carpel,  it  were  surely 
no  greater  anomaly  for  the  elements  of  such  half-stigmas  as  those  of  Drosera  to 
follow  the  same  course.  This  is  precisely  what  takes  place  in  Parnassia,  and  in 
other  cases  where  the  stigmas  are  opposite  the  parietal  placenta; ;  —  cases  which 
were  thought  to  be  very  anomalous,  merely  on  account  of  the  adoption  of  a 
false  principle  (that  of  the  necessary  alternation  of  the  stigmas  and  placentae), 
but  which  are  really  no  more  extraordinary  than  parietal  placentation  itself 

3.  Furthermore,  the  production  of  ovules  is  not  always  restricted  to  what 
answers  to  the  margins  of  the  carpellary  leaves.  In  the  Poppy,  the  whole  sur- 
face of  the  long,  imperfect  partitions  is  covered  with  ovules  ;  in  Butomus,  they 
are  borne  over  the  whole  internal  face  of  each  carpel,  and  in  Water-Lilies  over 
the  whole  surface,  except  the  inner  angle  of  each  cell,  where  alone  they  normally 
belong.  Reduced  to  two  in  the  allied  Water-Shield  (Brasenia,  Fig.  684),  the 
ovules  grow  from  the  dorsal  suture,  or  the  midrib  of  the  carpellary  leaf  alone  ! 
And  in  the  allied  Cabomba  itself  we  usually  find  its  three  ovules,  one  on  the 
dorsal  and  one  on  the  ventral  suture,  and  the  third  on  some  variable  part  of  the 
face  of  the  cell  in  the  vicinity  of  either  suture.  In  Obolaria,  Bartonia  (Centau- 
rella,  Michx.),  and  in  several  species  of  Gentian,  a  compound  one-celled  ovary  is 
ovuliferous  over  the  whole  face  of  the  cell ! 

All  placentation  is  very  differently  explained  by  those  who  adopt  the  hypoth- 

FIG.  510.  Pistil  of  Drosera  filiformis,  with  three  deeply  two-parted  styles  :  the  ovary  cut 
across,  showing  three  parietal  placentae. 


THE    COMPOUND    PISTIL.  295 

558.  When  the  styles  are  separate  towards  the  summit,  but 
united  below,  they  are  usually  described  as  a  single  organ ;  which 
is  said  to  be  parted,  cleft,  lobed,  &c,  according  to  the  extent  of  cohe- 
sion. This  language  was  adopted,  as  in  the  case  of  leaves  (281) 
and  floral  envelopes  (4G2),  long  before  the  real  structure  was  under- 


csis  of  Schlcidcn,  Endlichcr,  and  others.  According  to  this  new  view,  since  buds 
regularly  arise  from  the  axils  of  leaves  and  from  the  extremity  of  the  stem  or 
axis,  and  only  in  some  exceptional  and  abnormal  cases  from  the  margins  or 
surface  of  leaves,  so  ovules,  which  are  viewed  as  a  form  of  buds,  are  considered 
to  arise  from  the  receptacle,  either  from  the  axis  of  the  flower,  like  terminal 
buds,  or  from  the  axils  of  the  carpellary  leaves,  like  axillary  buds.  Thus, 
placenta;  are  supposed  to  belong  to  the  stem,  and  not  to  the  carpellary  leaves  ; 
and  a  one-celled  ovary,  with  one  or  more  ovules  arising  from  the  base  of  the 
cell,  would  nearly  represent  the  typical  state  of  the  gynsecium.  This  theory, 
which  the  intelligent  student  may  easily  apply  in  detail,  offers  a  ready  explana- 
tion of  free  central  placcntation,  especially  in  such  cases  as  Primula,  &c,  where 
not  a  trace  of  dissepiments  is  ever  discoverable.  But  in  Caryophyllaceaa  the 
dissepiments  are  often  manifest.  In  applying  it  to  ordinary  central  placenta- 
tion,  we  have  to  suppose  the  cohesion  of  the  inflexed  margins  of  the  carpellary 
leaves  with  a  central  prolongation  of  the  axis  or  receptacle  which  bears  the 
placenta;.  But  in  parietal  placcntation,  the  advocates  of  this  theory  are  driven 
to  the  violent  supposition  that  the  axis  divides  within  the  compound  ovary  into 
twice  as  many  brandies  as  the  carpels  in  its  composition,  and  that  these  branches 
regularly  adhere,  in  pairs,  one  to  each  margin  of  all  the  carpellary  leaves.  Its 
application  is  attended  with  still  gi-eatcr  difficulties  in  the  case  of  simple  and 
uncombined  pistils,  where  the  ovules  occupy  the  whole  inner  suture,  which  must 
be  taken  as  the  typical  state  of  the  gyna;cium  ;  but  to  which  the  new  hypothesis 
can  be  adapted  only  by  supposing  that  an  ovuliferous  branch  of  the  axis  enters 
each  carpel,  and  separates  into  two  parts,  one  cohering  with  each  margin  of  the 
metamorphosed  leaf.  This  view,  however,  not  only  appears  absurd,  but  may 
be  disproved  by  direct  observation,  as  it  has  been  most  completely  by  those 
monstrosities  in  which  an  anther  is  changed  into  a  pistil,  or  even  one  part  of 
the  anther  is  thus  transformed  and  bears  ovules,  while  the  other,  as  well  as  the 
filament,  remains  unchanged  ;  —  a  case  where  the  ovules  are  far  removed  from 
anything  which  can  possibly  belong  to  the  axis.  We  may  further  remark,  that 
even  the  appearance  of  a  placenta  or  ovuliferous  body  in  the  apparent  axil  of  a 
carpellary  leaf  no  more  proves  that  the  body  in  question  belongs  to  the  axis, 
than  that  the  appendage  before  the  petals  of  Parnassia  and  the  American  Lin- 
den represents  a  branch  instead  of  a  leaf.  As  to  the  terminal  naked  ovule  of 
the  Yew,  where  the  structure,  on  any  view,  is  reduced  to  the  greatest  possible 
simplicity,  it  is  surely  as  probable  that  it  answers  to  the  earliest  formed,  or 
foliar,  portion  of  the  ultimate  phyton,  here  alone  developed,  as  to  the  cauline  part, 
which  so  seldom  appears  in  the  flower.  The  most  important  of  these  points 
are  elucidated  by  Mr.  Brown,  in  Plantce  Jaranicce  Rariores,  pp.  107-112,  in 
two  notes,  which  apparently  are  not  sufficiently  studied  by  botanists. 


296 


THE    FLOWER. 


stood :  but,  as  it  involves  an  erroneous  idea,  the  expressions,  Styles 
distinct ;  united  at  the  base ;  united  to  the  middle,  or  summit,  &c, 
as  the  case  may  be,  should  be  employed  in  preference. 

559.  A  few  casual  exceptions  occur  to  the  general  rule  that 
ovules  and  seeds  are  both  produced  and  matured  within  an  ovary, 
namely,  in  a  closed  carpellary  leaf  or  set  of  combined  carpellary 
leaves.  In  the  Blue  Cohosh  (Caulophyllum  thalictroides)  the  ovules 
rupture  the  ovary  soon  after  flowering,  and  the  seeds  become  naked ; 
and  in  Mignonette  they  are  imperfectly  enclosed,  the  ovary  being 
open  at  the  summit  from  an  early  period.  In  all  such  cases,  how- 
ever, the  pistil  is  formed  and  the  ovules  are  fertilized  in  the  ordi- 
nary way. 

500.  GynffiCilim  Of  GymnospermoilS  Plants.  A  far  more  remarkable 
exception  is  presented  by  two  natural  families,  viz.  Conifera?  (Pines, 

Firs,  &c.)  and  Cycadaceoe 
(Cycas,  Zamia).  Here 
the  pistil,  as  likewise  the 
Avhole  flower,  is  reduced  to 
the  last  degree  of  simplici- 
ty ;  each  fertile  flower  con- 
sisting merely  of  an  open  carpellary  leaf,  in  place  of  an  ordinary  pistil, 
in  the  form  of  a  scale  (Fig.  511  -  513,  515,  51G),  or  of  some  other 
shape,  and  bearing  two  or  more  ovules 
upon  some  part  of  its  upper  surface.  At 
the  time  of  blossoming,  these  pistil-leaves 
of  the  forming  cone  diverge,  and  the  pol- 
len, abundantly  shed  from  the  staminate 
blossoms,  falls  directly  upon  the  exposed 
ovules.  Afterwards  the  scales  close  over 
each  other  until  the  seeds  are  ripe.  In  the 
Yew  there  is  no  carpel  or  pistil-leaf  at  all ; 
but  the  fertile  blossom  consists  of  a  solitary 
naked  ovule,  borne  on  the  extremity  of  a  515  516 

FIG.  511.  Scale,  i.  e.  open  pistil,  from  the  cone  of  a  Larch,  at  the  time  of  flowering,  or  a 
little  later ;  the  upper  side  seen,  with  its  pair  of  naked  ovules. 

FIG.  512.  Similar  view  of  a  Larch  scale,  when  the  seeds  are  partly  grown.  513.  A  mature 
scale,  one  of  the  seeds  in  its  place,  the  other  fallen  (reduced  in  size).  514.  A  seed  detached, 
with  its  wing. 

FIG.  515.  Branchlet  of  the  American  Arbor-Vitas,  considerably  larger  than  in  nature,  ter- 
minated by  its  pistillate  flowers,  each  consisting  of  a  single  scale  (an  open  pistil),  together 
forming  a  small  cone.  51G.  One  of  the  scales  or  pistils  removed  and  more  enlarged,  the  inside 
exposed  to  view,  showing  a  pair  of  naked  ovules  ou  its  base. 


THE    OVULE. 


297 


short  branch,  and  surrounded  by  a  few  small  bracts.  As  the  ovules 
are  here  naked  and  exposed  to  the  direct  contact  of  the  pollen,  and 
the  seeds  are  not  enclosed  in  anything  answering  to  a  pod,  these 
have  received  the  name  of  Gymnospermous  Plants,  that  is,  plants 
with  naked  seeds. 


Sect.  VIII.     The  Ovule. 


561.  Ovules  (420,  543)  are  bodies  borne  by  the  pistil,  which,  on 
being  fertilized  and  having  an  embryo  developed  in  them,  become 
seeds.  To  their  formation,  fertilization,  and  protection  all  the  other 
parts  of  the  blossom  are  subservient.  They  vary  greatly  in  num- 
ber, from  one  (solitary)  in  each  carpel  or  cell  to  a  multitude.  "When 
few  and  uniform  in  number,  they  are  said  to  be  definite  ;  when  too 
numerous  to  be  readily  counted,  indefinite. 

562.  As  to  situation  and  direction,  they  are  erect  when  they  arise 
from  the  very  bottom  of  the  cell  (Fig.  518)  ;  ascending,  Avhen  fixed 
above  its  base  and  rising  obliquely 
upwards  (Fig.  517)  ;  horizontal, 
when  they  project  from  the  side  of 
the  cell,  without  turning  either  up- 
wards or  downwards  (Fig.  342)  ; 
pendulous,  when  they  hang  or  turn 
obliquely  downwards  (Fig.  387)  ; 
and  suspended  when  hanging  perpendicularly  from  the  very  summit 
of  the  cell  (Fig.  519).  These  terms  apply  to  the  seed  as  well  as  to 
the  ovule. 

563.  An  ovule  is  at  first  a  minute  projection  of  the  placenta  (Fig. 
530),  of  soft  and  homogeneous  parenchyma;  but  it  soon  acquires  a 
definite  form  and  structure.  It  may  be  either  sessile,  or  raised  on  a 
stalk,  the  Funiculus,  Podosperm:,  or  seed-stalk.  The  point  of 
attachment,  which  in  the  seed  forms  the  scar,  is  called  the  Hilum. 

564.  It  consists  of  a  kernel  or  nucleus,  and  usually  of  one  or  two 
coats.  The  nucleus  is  the  essential  part  of  the  organ ;  in  it  the 
embryo  is  formed,  and  the  coats  become  the  integuments  of  the 
seed.  The  ovule  of  the  Mistletoe  consists  of  a  naked  nucleus  only, 
there  being  no  integument.     The  ovule  of  the  Walnut  has  only  one 


FIG.  517.     Ovary  of  a  Buttercup,  divided  lengthwise,  to  display  its  ascending  ovule.     518. 
Same  of  Buckwheat,  with  an  erect  ovule.    519.  Same  of  Anemone,  with  a  suspended  ovule. 


298 


THE   FLOWER. 


coat :  this  appears  as  a  circular  ring  around  the  base  of  the  forming 
nucleus,  which  gradually  becomes  cup-shaped,  and  at  length  covers 
it    like   a  sac,  remaining   open,   however,   at    the    summit.      This 

orifice  is  called  the  Foramen, 
or  Micropyle.  In  far  the 
greater  number  of  cases,  a 
second  envelope  is  formed  out- 
side of  the  first,  beginning  in 
the  same  way,  though  always 
later  than  the  inner  one,  which, 
however,  it  eventually  over- 
takes and  encloses.  Mirbel 
named  the  exterior  coat  of  the 
ovule  the  Primine,  and  the  in- 
terior the  Secundine, —  names  which  are  attended  with  the  objec- 
tion that  the  secundine  or  inner  coat  is  actually  older  than  the 
primine  or  exterior  coat.  Both  sacs  are  open  at  the  apex,  and  the 
summit  of  the  nucleus  points  directly  towards  the  apertures.  The 
orifice  or  foramen  of  the  primine  or  exterior  integument  is  called 
the  Exostome  (or  outer  orifice)  ;  that  of  the  interior  or  secundine, 
the  Endostome  (or  inner  orifice).  The  coats  of  the  ovule  and 
the  nucleus  are  distinct  and  unconnected,  except  at  the  base,  or  point 
of  attachment  to  the  funiculus,  where  they  are  all  confluent :  this 
point  of  union  receives  the  name  of  the  Chalaza  (Fig.  521,  d). 
Through  the  funiculus  and  chalaza  the  ovule  derives  its  nourish- 
ment from  the  placenta ;  through  the  opening  at  the  summit,  the 
nucleus  receives  the  tubular  prolongation  of  the  pollen,  which  incites 
the  formation  of  the  embiyo. 

565.  Ovules  occur  under  four  principal  forms,  viz.  the  orthotro- 
pous  or  straight,  the  campylotropous  or  curved,  the  amphitropous  or 
half-inverted,  and  the  anatropous  or  inverted.  The  simplest,  al- 
though the  least  common  of  these,  is 

5G6.  The  OrtllOtropom  Ovule,  also  termed  atropons  (viz.  not  turned). 
It  is  the  form  which  this  organ  assumes  in  the  Buckwheat  family 
(Fig.  518),  and  several  others,  and  is  likewise  shown  in  Fig.  520, 
526,  and  a  longitudinal  section  of  it  in  Fig.  521.     Here  no  change  in 

FIG.  520.  An  orthotropous  ovule.  521.  Longitudinal  section  of  the  same,  more  magnified : 
a,  the  primine  ;  b,  the  secundine ;  c,  the  nucleus  ;  d,  the  chalaza.  522.  An  amphitropous 
ovule.  523.  Three  anatropous  ovules,  with  long  funiculi,  attached  to  a  portion  of  the  placenta. 
524.  One  of  the  same,  more  highly  magnified,  exhibiting  its  cellular  structure.  525.  A  campy- 
lotropous ovule. 


THE    OVULE.  299 

the  direction  of  parts  occdrs  during  growth ;  hut  the  base  or  ehalaza 
(Fig.  526,  c)  is  manifestly  the  point  of  attachment,  the  orifice  (/) 
is  at  the  opposite  end,  and  the  ovule  is  straight  and  symmetrical. 


567.  The  Campylotropous  Ovule  (Fig.  525,  527)  is  one  which  grows 

unequally,  and  consequently  curves  upon  itself,  so  as  to  bring  the 
apex  round  to  the  vicinity  of  the  base,  the  ehalaza  (c)  and  the  orifice 
(f)  being  at  length  brought  nearly  into  contact  at  the  point  of  at- 
tachment. Campylotropous  or  curved  ovules  are  found  in  the  Mig- 
nonette, in  all  Cruciferous  and  Caryophyllaceous  plants,  and  in  many 
others. 

568.  The  Anatropous  Ovule  (Fig.  517,  519,  523,  524,  529)  is  far 

the  most  common  form.  It  is  best  described  by  likening  it  to  an 
orthotropous  ovule  which  as  it  grew  had  inverted  itself  on  its  funicu- 
lus or  support,  so  that,  while  the  body  remains  straight,  its  orifice  or 
apex  is  brought  down  to  the  funiculus  and  points  to  the  placenta, 
while  the  ehalaza  occupies  the  apparent  or  geometrical  apex,  i.  e.  the 
summit  or  point  directly  opposite  the  place  of  attachment.  The 
ovule,  thus  inverted  on  its  support,  coheres  with  it  for  its 
whole  length,  and  accordingly  has  a  ridge  or  cord,  more 
or  less  manifest,  along  one  side  (Fig.  529,  r),  connect- 
ing the  hilum,  or  place  of  attachment,  and  where  the 
seed  separates  from  its  insertion  (h),  with  the  ehalaza  (c). 
This  cord  or  ridge,  which  morphologically  is  merely  a 
continuation  of  the  stalk  or  support  of  the  ovule  adhe- 
rent to  its  face  on  one  side,  or  incorporated  with  it,  is 
called  the  Rhaphe.  It  is  a  distinguishing  mark  of  an 
anatropous  ovule,  which  is  also  recognizable  by  its  so 
being  straight  and  by  having  the  orifice  close  to  the  point  of  attach- 
ment.    The  rhaphe  itself  is  often  so  incorporated  with  the  coat  of 

FIG.  526.    Orthotropous  orule  of  Buckwheat :  e,  hilum  and  ehalaza  ;  /,  orifice. 
FIG.  527.     Campylotropous  ovule  of  a  Chickweed  :  c,  hilum  and  ehalaza  ;  /,  orifice. 
FIG.  528.    Amphitropous  ovule  of  Mallow  :  /,  orifice  ;  h,  hilum  ;  r,  rhaphe  ;  c,  ehalaza. 
FIG.  529.     Anatropous  ovule  of  a  Violet ;  the  parts  lettered  as  in  the  last. 
FIG.  530.    Vertical  section  of  a  pistil  of  Magnolia  Umbrella,  from  a  young  flower-bud,  mag- 
nified, showing  the  forming  ovule,  here  a  simple  protuberance. 


300 


FERTILIZATION. 


the  ovule  or  the  seed  as  to  he  externally  undistinguishable.  The 
seeds  of  Magnolia  offer  good  illustrations  of  this.  The  mode  of 
formation  and  the  internal  structure  of  anatropous  or  inverted  ovules 
will  be  apparent  on  inspection  of  Fig.  530-536. 


5G9.  The  Ampllitropous  Ovule  (Fig.  522,  528),  also  called  heterotro- 
pous,  differs  from  the  anatropous  in  having  a  short  rhaphe  (Fig. 
528,  r),  extending  from  the  chalaza  (e)  only  about  half-way  to  the 
orifice  {/)■  It  is  attached  accordingly  by  the  middle  of  one  side, 
and  has  the  chalaza  at  one  end  and  the  orifice  at  the  other.  It  may 
be  regarded  as  a  half-anatropous  or  half-inverted  ovule  ;  and  all  gra- 
dations occur  between  this  and  the  anatropous  form,  into  which  it 
would  pass  by  the  cohesion  of  the  side  of  the  ovule  with  the  support 
a  little  farther  down.  Amphitropous  ovules  are  general  in  the  Mal- 
low and  the  Primrose  families.  As  such  an  ovule  stands  with  its 
axis  at  right  angles  with  the  funiculus,  if  there  be  any,  it  is  also  said 
to  be  transverse. 

570.  Most  of  these  terms  apply  to  seeds  as  well  as  to  ovules ;  and 
the  general  structure  of  the  seed  may  be  known  beforehand  from 
that  of  the  ovules.  We  are  now  prepared  to  contemplate  the  pro- 
cess by  which  an  ovule  becomes  a  seed. 


Sect.  IX.     Fertilization  and  Formation  of  the  Embryo. 

571.  In  order  to  the  formation  of  the  embryo  (118),  the  ovules 
require  to  be  fertilized  by  the  pollen.  Cases  of  parthenogenesis, 
i.  e.  of  the  formation  of  perfect  seed  without  the  agency  of  pollen, 
doubtless   do  sometimes   occur,  and   have   been  noted   in   several 


FIG.  531.  A  similar  side-view  of  the  ovule  of  the  last,  a  week  or  two  later,  and  more  mag- 
nified ;  showing  the  nucleus  encircled  by  the  coats  in  formation,  as  two  rings  or  shallow  cups 
one  within  the  other.  532.  The  same,  a  few  days  later,  more  advanced  and  beginning  to  turn. 
533.  The  same,  further  advanced.  534.  The  same,  soon  after,  with  the  inversion  almost 
complete,  and  the  outer  coat  covering  the  inner,  except  at  the  orifice.  535.  The  completed 
anatropous  ovule  rom  a  full-grown  flower-bud.  536.  A  longitudinal  section  of  the  same, 
displaying  the  rhaphe,  the  two  coats,  and  the  nucleus. 


THE  ACCESS  OP  THE  POLLEN.  301 

dioecious  plants.  More  than  half  a  century  ago,  Spallanzani  found 
that  the  pistillate  blossoms  of  Hemp  may  produce  fertile  seed  with- 
out the  concurrence  of  pollen  ;  and  recently  Naudin  and  Decaisne 
have  confirmed  the  fact  by  experiment,  and  from  seeds  produced 
without  fertilization  have  raised  a  second  generation  of  plants,  the 
pistillate  individuals  of  which,  kept  from  all  access  of  pollen,  have 
themselves  ripened  seeds  with  perfect  embryos.*  Two  or  three 
dioecious  Euphorbiaceous  plants  are  known  to  produce  good  seed 
under  the  same  circumstances,  and  Naudin  has  shown  it  freely  to 
occur  in  Bryony.  Still  these  are  very  exceptional  cases,  and  are  all 
confined,  so  far  as  known,  to  dioecious  plants.  Ordinarily  the  access 
of  pollen  of  the  species  to  the  ovules  is  necessary  to  the  production 
of  the  embryo. 

572.  The  Access  Of  the  Pollen  to  the  pistil  is  secured  in  a  great 
variety  of  ways  and  adaptations.  In  hermaphrodite  blossoms  the 
relative  length  and  position  of  the  stamens  and  stigmas  are  com- 
monly so  adjusted  that  the  pollen  may  fall  directly  upon  the 
stigma,  the  anthers  being  usually  higher  than  the  stigmas  when 
the  flower  is  upright,  and  shorter  when  it  is  nodding.  Sometimes 
pollen  is  projected  upon  the  stigma  by  transient  and  often  sudden 
movements,  either  mechanical,  as  in  Kalmia,  or  spontaneous  and 
vital,  as  in  the  Barberry  (to  be  mentioned  in  another  place).  Some- 
times fertilization  takes  place  in  the  bud,  where  the  parts  are  in 
apposition,  or  the  anthers  are  kept  in  contact  with  or  proximity  to 
the  stigma,  as  in  papilionaceous  flowers  by  the  enclosing  keel-petals, 
and  in  the  Fumitory  family  by  a  close-fitting  little  sac  formed  of  the 
united  spoon-shaped  tips  of  the  two  inner  petals  confining  the  an- 
thers to  the  stigma.  Very  often  the  pollen  is  conveyed  from  the 
anthers  to  the  stigma  by  insects,  searching  for  honey  or  nectar ;  and 
there  are  many  species  in  which  fertilization  seems  absolutely  to 
depend  upon  the  agency  of  insects  ;  such,  for  instance,  as  those  of 
Aristolochia,  Asclepias  or  Milkweed,  and  many  plants  of  the  Orchis 
family.  In  dioecious  and  many  monoecious  plants,  with  widely  sep- 
arated blossoms,  fertilization  is  mainly  dependent  upon  insects,  pass- 
ing from  flower  to  flower,  and  upon  winds  and  currents.  And  the 
immense  quantity  of  pollen  which  many  such  plants  produce  com- 
pensates for  the  greater  distance  of  the  passage,  and  greatly  dimin- 
ishes the  chance  of  failure.     The  air  of  a  Pine  forest  in  flowering- 

*  Comptes  Rendus,  Vol.  43,  1856,  and  Hooker's  Journal  of  Botany,  1857,  p.  53. 
26 


302 


FERTILIZATION. 


time  is  almost  loaded  with  pollen,  some  of  which  is  often  wafted  by 
the  winds  for  many  miles. 

573.  The  pollen  of  Pines  and  other  Gymnospennous  plants  falls 
directly  upon  the  naked  and  exposed  ovules  (560).  On  all  others, 
the  ovules,  being  secluded  in  a  closed  ovary,  can  be  fertilized  only 
through  the  stigma.  In  these,  accordingly,  we  have  first  to  con- 
sider. 

574.  The  Action  of  Pollen  on  the  Stigma.    The  loose  papillae;  or 

often  the  short  projecting  hairs  of  the  stigma,  and  the  moist  surface, 
serve  to  retain  the  grains  of  pollen  on  the  stigma  when  they  have 
once  reached  it.  Absorbing  some  of  this  moisture,  and  nourished 
by  it,  the  grains  of  pollen  which  are  favorably  situated  soon  begin 
to  grow,  oi*,  as  Ave  may  say,  to  germinate.  The  thin  inner  mem- 
brane (534)  extends,  breaks  through  the  thicker,  but  weak  or  brittle, 
outer  coat  at  some  point  (or  rarely  at  two  or  three  places),  and 
lengthens  into  a  delicate  tube,  filled  with  the  liquid  and  molecular 
matter  that  the  grain  contains.  This  tube  (Fig.  537  —  540), remain- 
ing closed  at  the  extremity,  penetrates  the  loose  tissue  of  the  stigma,, 
and  is  prolonged  downwards  into  the  style,  gliding  along  the  inter- 
spaces between  the  very  loosely  disposed  cells  of  the  moist  conduct- 
ing tissue  (541),  which  extends  from  the  stigma  to  the  cavity  of  the 
ovary,  and  at  length  reaches  the  placenta, 
or  some  other  part  of  the  lining  of  the 
ovary,  and  its  extremity  appears  in  the 
cell.  This  prolongation  into  a  tube,  often 
many  hundred  times  the  diameter  of  the 
pollen-grain,  is  a  true  growth,  after  the  man- 
ner of  elongating  cells  (37-97),  nourished 
by  the  organizable  moisture  of  the  style 
which  it  imbibes  in  its  course.  Now  the 
orifice  of  the  ovules,  or  a  projection  of 
the  nucleus  beyond  the  orifice,  is  at  this 
time  brought  into  contact  with,  or  close 
proximity  to,  that  portion  of  the  walls  of  the  ovary  from  which  the 
pollen-tubes  project ;  and  a  pollen-tube  thus  enters  the  orifice  of 
each  ovule,  and  reaches  the  nucleus,  in  which  the  nascent  embryo 

FIG.  537.  A  pollen-grain  of  Datura  Stramonium,  emitting  its  tube.  538.  Pollen-grain  of 
a  Convolvulus,  with  its  tube.  539.  Other  pollen-grains,  with  their  tubes,  less  strongly  mag- 
nified. 540.  A  pollen-grain  of  the  Evening  Primrose,  resting  on  a  portion  of  the  stigma,  into 
which  the  tube  emitted  from  one  of  the  angles  penetrates  ;  the  opposite  angle  also  emitting  a 
pollen-tube. 


THE    ACTION    OF    THE    POLLEN. 


303 


subsequently  appears.  In  Gymnospermous  plants  (5  GO,  573),  the 
pollen-grains  grow  at  the  orifice  of  the  naked  ovule,  and  immediately 
penetrate  its  nucleus,  just  as  they  do  the  stigma  in  ordinary  plants. 

575.  Pollen-tubes  may  be  readily  inspected  under  the  microscope 
in  many  plants  ;  in  none  more  readily  than  in  the  Asclepias,  or 
Milkweed,  one  of  the  plants  in  which  this  subject  was  so  admirably 
investigated  by  Mr.  Brown.  In  that  family,  the  pollen-grains  of 
each  cell  of  the  anther  (Fig.  541)  cohere  in  a  mass  ;  and  these 
pollen-masses,  dislodged  from  their  cells  (Fig.  542,  543),  usually  by 
the  agency  of  insects,  and  brought  into  proximity  with  the  base  of 
the  stigma,  protrude  their  tubes  in  great  abundance.  They  may  be 
seen  to  penetrate  the  base  of  the  stigma,  as  in  Fig.  544,  and  sepa- 
rate grains  with  their  tubes  may  be  detached  from  the  mass  (Fig. 
546,  547) ;  but  to  trace  their  course  down  the  style  (as  in  Fig.  545), 
and  to  their  final  destination,  requires  much  skill  in  manipulation 
and  the  best  means  of  research. 

576.  The  formation  of  the  pollen-tube  commences  in  some  cases 
almost  immediately 
upon  the  applica- 
tion of  the  pollen 
to  the  stigma ;  in 
others  it  is  not  per- 
ceptible until  after 
the  lapse  of  from  ten 
to  thirty-six  hours 
or  more.  The  rate 
of  the  growth  of  the 
pollen-tube  down 
the  style  is  also 
very  various  in  dif- 
ferent plants.  In 
some  species,  a  week  or  more  elapses  before  they  have  passed 
through  a  style  even  of  a  few  lines  in  length.     In  others,  a  few 


FIG.  541.  A  back  view  of  a  stamen  of  the  common  Milkweed  (Asclepias),  the  appendage 
cut  away.  542.  A  stamen  more  magnified,  with  the  two  pollen-masses  cohering  by  their  cau- 
ilicles,  each  to  a  gland  from  the  summit  of  the  stigmatic  body,  to  which  a  pollen-mass  from  an 
adjacent  anther  is  already  adherent.  543.  A  pair  of  detached  pollen-masses  (each  from  a  dif- 
ferent anther)  suspended  by  their  caudicles  from  the  gland.  544.  Some  of  the  pollen-masses, 
with  their  tubes  penetrating  the  stigma  (after  Brown).  545.  A  section  through  the  large  stig- 
matic body  and  a  part  of  the  summit  of  one  of  the  styles,  showing  the  course  of  the  pollen- 
tubes.  546,  547.  Pollen-grains  with  their  tubes,  highly  magnified.  (The  structure  of  these 
singular  flowers  will  be  more  fully  explained  under  the  order  Asclepiadacea.) 


304  FERTILIZATION. 

hours  suffice  for  their  passage  through  even  the  longest  styles,  such 
as  those  of  Colchicum,  Mirabilis  or  Four-o'clock,  and  Cereus  grandi- 
florus.  After  the  pollen-tubes  have  penetrated  the  stigma,  the  latter 
dries  up,  and  its  tissue  begins  to  wither  or  die  away,  as  likewise 
does  the  body  of  the  pollen-grain,  its  whole  contents  being  trans- 
ferred to  the  pollen-tube,  the  lower  part  of  which  may  still  be  in  a 
growing  condition. 

577.  Before  the  pollen-tube  has  reached  the  ovule,  or  more  com- 
monly even  before  the  pollen  is  applied  to  the  stigma,  a  cavity  ap- 
pears in  the  interior  of  the  nucleus  of  the  ovule,  near  its  apex. 
This  probably  results  from  the  special  growth  of  a  particular  cell, 
which  expands  into  a  bladder  or  closed  sac,  at  length  commonly  oc- 
cupying a  considerable  part  of  the  nucleus,  —  sometimes  remaining 
enclosed  in  its  tissue  towards  its  summit  or  orifice,  sometimes  dis- 
placing the  upper  part  of  the  nucleus  entirely,  or  even  projecting 
through  the  micropyle.  This  is  the  sac  of  the  amnios  of  Mr.  Brown, 
the  embryo-sac  (sac  cmbryonaire)  of  the  French  botanists.  In  this 
sac  the  embryo  is  formed. 

578.  Origin  of  the  Embryo.  From  the  latter  part  of  the  seven- 
teenth century,  when  the  relative  functions  of  the  stamens  and  the 
pistils,  and  something  of  the  structure  of  the  ovule,  were  demon- 
strated by  Malpighi,  Grew,  &c,  until  about  the  year  1837,  it  was 
almost  universally  supposed  that  the  embryo  was  a  product  of  the 
ovule,  in  some  way  incited  or  fertilized  by  the  pollen.  One  writer, 
viz.  Samuel  Morland,  had  indeed  propounded  the  crude  hypothesis, 
that  a  pollen-grain  itself,  descending  bodily  through  the  style,  Avas 
received  into  the  orifice  of  the  ovule,  and  became  the  embryo.  The 
absurdity  of  this  view  was  soon  made  evident.  But  how  the  pollen 
acted  was  wholly  unknown  until  Amici,  in  1823,  discovered  pollen- 
tubes,  penetrating  the  stigma,  and  Brongniart,  Brown,  Amici  himself, 
and  Schleiden,  within  the  ensuing  twelve  or  fourteen  years,  had 
demonstrated  their  universality,  and  traced  these  slender  tubes  into 
the  ovary,  and  even  to  the  nucleus  of  the  ovule.  Then  commenced  a 
spirited  controversy,  which  has  only  just  now  been  brought  to  a  close. 
For  Professor  Schleiden,  in  the  year  1837,  advanced  the  view  that  the 
extremity  of  the  tube  of  the  pollen,  entering  the  nucleus  of  the  ovule, 
there  developed  into  the  embryo,  —  thus  anew  deriving  the  embryo 
or  new  plant  substantially  from  the  pollen  instead  of  the  ovule. 
This  view  has  recently  been  abandoned  by  its  indefatigable  author 
and  his  most  able  supporter,  Schacht,  having  been  thoroughly  dis- 


ORIGIN    OF    THE    EMBRYO.  305 

proved  in  all  points  by  a  series  of  elaborate  investigations  made  by 
Mirbel,  Amici,  Giraud,  Mold,  Hofmeister,  Unger,  Tulasne,  Henfrey, 
and  Radlkofer.  So  that  —  passing  by  the  whole  history  of  this  long 
discussion,  and  merely  appending  some  references  to  the  more  im- 
portant publications  upon  the  subject  *  —  we  need  only  state  here, 
in  the  most  general  terms,  the  principal  facts  which  are  now  held 
to  be   established,  viz. :  — 

579.  The  pollen-tube  terminates  on  the  outer  surface  of  the 
embryo-sac,  or  sometimes,  perhaps,  forces  its  way  into  it.  Ordina- 
rily its  extremity  becomes  firmly  adherent,  to  the  surface  of  the 
embryo-sac,  and  it  appears  to  remain  closed.  Henfrey,  indeed,  is 
led  to  suppose  that  the  membrane  of  the  pollen-tube  and  that  of  the 
embryo-sac  are  absorbed  at  the  point  of  contact,  and  that  the  former 
thus  discharges  its  contents  into  the  cavity  of  the  latter ;  but  this  is 
merely  an  unproved  inference,  suggested  by  the  analogy  of  what  is 
now  known  of  the  process  of  fecundation  in  Cryptogamous  plants. 
At  present  it  appears  most  probable  that  the  contents  of  the  pollen- 
tube  are  drawn  into  the  embryo-sac  by  endosmosis.  However  this 
may  be,  shortly  after  reaching  the  embryo-sac  the  pollen-tube  be- 
comes empty,  and  decays  or  withers  away.  Meanwhile  the  body 
which  by  its  development  is  to  give  rise  to  the  embryo  appears  in 
the  embryo-sac  independent  of  the  pollen-tube.  According  to  most 
investigators  it  generally  appears  before  the  pollen-tube  has  entered 
the  ovule.     (The  high  authority  of  Tulasne,  however,  is  thus  far 


*  Schlciden  first  published  his  famous  theory  in  Wiegmann's  Archiv,  1837, 
and  in  Acta  Nova  Acad.  Nat.  Cur.,  Vol.  19.  It  was  extended  and  defended  in 
his  systematic  works,  —  and  especially  by  Schacht  in  Trans.  Netherlands  Insti- 
tute, 1850,  in  Bot.  Zeitung,  1855  (transl.  in  Ann.  Sci.  Nat.  of  that  year),  in  his 
Beitrdge  Anat.  fy  Phys.,  in  his  work  on  the  microscope,  of  which  an  English 
translation  by  Dr.  Currey  was  published  in  1855,  and  in  the  Eegensberg 
Flora,  1855  (Ann.  Sci.  Nat.  1855).  See  also  Deecke  in  Bot.  Zeitung,  1855 
(Ann.  Sri.  Nat.,  1.  c.).  On  the  other  side  of  the  question  the  most  important  of 
the  recent  publications,  since  the  appearance  of  Mold's  Principles  of  the  Anatomy 
and  Physiology  of  the  Vegetable  Cell,  in  the  English  translation  (1852),  and  the 
article  Ovule  in  the  Micrographic  Dictionary  by  Henfrey,  are  :  Hofmeister,  in 
Flora,  May,  1855,  and  Mold,  in  Bot.  Zeitung,  June,  1855  (both  reproduced  in 
Ann.  Sci.  Nat.,  ser.  4,  Vol.  3,  1855) ;  Tulasne,  in  Ann.  Sci.  Nat.,  scr.  4,  Vol.  4, 
1855,  being  the  complement  of  his  great  memoir  published  in  the  same  journal 
(ser.  3,  Vol.  12,  1849)  ;  Eadlkofer,  Die  Befruchtung  der  Phanerogam irn,  Lcipsic, 
1856  ;  Henfrey,  Development  of  the  Ovule  of  Santalum  album,  &c,  in  Trans.  Linn. 
Soc.,  Vol.  22,  part  1,  1856. 

26* 


306 


FERTILIZATION. 


opposed  to  the  pre-existence.)  It  is  a  small  mass  or  globule  of  pro- 
toplasmic matter,  either  loose  in  the  cavity  of  the  embryo-sac  near 
the  place  to  which  the  pollen-tube  is  applied  externally,  or  else  ad- 
herent to  the  interior  surface  of  the  wall  of  the  embryo-sac  in  this 
immediate  vicinity,  or  sometimes  separated  from  the  embryo-sac  by 
an  interposed  globule,  or  by  a  pair  of  such  globules.  This  body,  the 
rudiment  of  the  future  embryo,  has  been  termed  the  embryonal  or 

germinal  vesicle.  This  is  not  yet  a 
cell ;  for  it  has  no  covering  or  wall 
of  cellulose.  But  it  soon  becomes 
one  when  a  pollen-tube  reaches  the 
embryo-sac,  the  first  known  result  of 
fertilization  being  that  a  coat  of  cel- 
lulose is  deposited  upon  its  surface. 
This  newly-formed  cell  grows  by 
cell-multiplication  (33),  either  pro- 
ducing a  mass  of  cells,  as  shown  in 
Fig.  10  -  14,  or  else  in  the  first  place 
developing  into  an  elongated  cell  or 
a  thread-shaped  chain  of  cells  (the 
suspensor),  the  lower  cell  of  which 
divides  in  all  directions,  forming  a 
mass,  which  as  it  grows  shapes  itself 
into  the  embryo  (Fig.  549-553). 
The  radicle  or  root-end  of  the  em- 
bryo is  always  that  by  which  it  is 
attached  to  the  suspensor  (which 
ordinarily  soon  disappears)  or  to  the 
summit  of  the  embryo-sac,  the  coty- 
ledons occupying  the  opposite  ex- 
tremity. The  radicle  accordingly 
is  always  directed  to  the  orifice  or 
micropyle  of  the  ovule  and  seed. 
580.  Through  the  fertilization  of  as  many  germinal  vesicles,  two 
or  more  embryos  are  frequently  found  in  the  same  seed,  in  the 
Orange,  the  Onion,  and  many  other  plants.     There  are  generally 


FIG.  548.  Magnified  pistil  of  Buckwheat ;  the  ovary  and  ovule  divided  lengthwise :  some 
pollen  on  the  stigmas,  one  grain  distinctly  showing  its  tube,  which  has  penetrated  the  style, 
reappeared  in  the  cavity  of  the  ovary,  entered  the  mouth  of  the  orthotropous  ovule  (o),  and 
reached  the  embryo-sac  (s),  near  the  embryonal  vesicle  (v). 


FORMATION  OF  THE  EMBRYO. 


307 


two  embryos  in  the  seed  of  the  Mistletoe  ;  and  there  is  usually  a 
plurality  of  embryos  in  Pines  and  other  Gymnospermous  plants 
(560),  though  all  but  one      519         550  551  532  533 

are  more  commonly  abor- 
tive or  rudimentary.    There 
are  other  striking  peculiar- 
ities in  the   fecundation  of 
Pines,  &c,  which,  however, 
cannot  be  readily  explained  without 
entering    into  more    detail    than    is 
here  advisable.*    In  Pines  and  their 
allies,  moreover,  the  embryo  is  not 
developed  until  a  long  time  after  the 
application   of   the   pollen,    and   the 
filling   of  the    embryo-sac    with    the 

cellular  tissue  which  forms  the  basis  of  the  albumen  of  the  seed ; 

the  fruit  and  seed  of 
true  Pines,  as  is  well 
known,  not  maturing  un- 
til the  year  after  that 
in  which  the  blossoms 
appear. 

580'.  The  further  development  and  the  structure  of  the  embryo 
and  the  seed  must  be  considered  after  the  Fruit,  of  Avhich  it  consti- 
tutes a  part. 


*  See  Hofmeister,  Untersuchungen,  &c. :  Researches  into  the  Fertilization,  &e. 
of  the  higher  Cryptogamia  and  the  Conifera?  (Leipsic,  1851),  with  seven  plates 
devoted  to  the  embryology  of  Conifcraj. 


FIG.  549.  Diagram  of  the  suspensor  and  forming  embryo  at  its  extremity.  550.  The  same, 
with  the  embryo  a  little  more  developed.  551.  The  same,  more  developed  still,  the  cotyledons 
faintly  indicated  at  the  lower  end.  552.  Same,  with  the  incipient  cotyledons  more  manifest. 
553.  The  embryo  nearly  completed. 

FIG.  554  -  556.  Forming  embryo  from  a  half-grown  seed  of  Buckwheat,  in  three  stages. 
557.  Same,  with  the  cotyledons  fully  developed. 


308 


THE    FRUIT. 


CHAPTER     X. 


OF   THE   FRUIT. 


Sect.  I.     Its  Structure,  Transformations,  and  Dehiscence. 


581.  The  fertilized  ovary,  increased  in  size,  and  usually  under- 
going some  change  in  texture  and  form,  becomes 

582.  The  Pericarp,  or  Seed-vessel.  The  pericarp  and  the  seeds  it 
contains  together  constitute  the  Fruit  ;  a  term  which  has  a  more 
extensive  signification  in  botanical  than  in  ordinary  language,  being 
applied  to  all  mature  pistils,  of  whatever  form,  size,  or  texture.  To 
the  fruit  likewise  belongs  whatever  organs  may  be  adnate  to  the 
pistils  (468).     Such  incorporated  parts,  like  the  fleshy  calyx  of  the 

Apple  and  Quince  (Fig.  809,  812),  sometimes 
make  up  the  principal  bulk  of  the  fruit. 

583.  Indeed,  the  calyx,  when  wholly  free 
from  the  pistil,  sometimes  becomes  greatly 
thickened  and  pulpy  after  flowering,  and  is 
transformed  into  what  appears  like  a  berry ; 
as  in  Gaultheria  (Fig.  913),  where  the  real 
fruit  is  a  dry  pod  Avithin  ;  and  in  Strawberry 
Blite  (Fig.  1099),  where  the  fleshy  calyxes  of 
a  head  of  flowers  each  surround  a  small  seed- 
like fruit,  and  together  form  a  false  multiple 
fruit,  resembling  a  strawberry. 

584.  Even  the  strawberry  itself  is  not  a 
fruit  in  the  strict  botanical  sense  :  that  is,  the 
edible  substance  is  not  a  ripened  pistil,  nor  a 
cluster  of  pistils,  but  is  the  receptacle  or  ex- 
tremity of  the  flower-stalk,  greatly  enlarged 
and  replete  with  delicious  juice  ;  the  true  fruits 
being  the  minute  and  seed-like  ripened  ovaries 
scattered  over  its  surface ;  as  plainly  appears 

from  a  comparison  of  Fig.  558  with  559.     Moreover,  a  mulberry, 


FIG.  55S.     Vertical  section  of  a  forming  strawberry,  enlarged. 

FIG.  559.     Similar  section  of  one  half  of  a  ripe  strawberry,  and  of  some  of  the  small  seed- 
like fruits,  or  achenia,  on  its  surface. 


ITS    STRUCTURE    AND    TRANSFORMATIONS.  309 

a  fig,  and  a  pine-apple  consist  of  the  ripened  products  of  many- 
flowers,  crowded  on  an  axis  or  common  receptacle,  which  makes  a 
part  of  the  edible  mass. 

585.  Under  the  general  name  of  fruit,  therefore,  even  as  the  word 
is  used  by  the  botanists,  things  of  very  different  structure  or  of  dif- 
ferent degrees  of  complexity  are  confounded.  We  must  distinguish, 
therefore,  between  simple  fruits,  resulting  from  a  single  flower,  and 
a  multiple  fruit,  resulting  from  the  parts  of  more  than  one  flower 
combined  or  collected  into  a  mass.  We  must  also  distinguish  be- 
tween true  fruits,  formed  of  a  matured  pistil,  either  alone  or  with  a 
calyx,  &c.  adnate  to  it,  and  fruits,  so  called,  of  which  the  pericarp 
does  not  form  an  essential  part. 

586.  Obliteration  or  Alteration.  The  pericarp,  being  merely  the 
pistil  matured,  should  accord  in  structure  with  the  latter,  and  con- 
tain no  organs  or  parts  that  do  not  exist  in  the  fertilized  ovary. 
Some  alterations,  however,  often  take  place  during  the  groAvth  of 
the  fruit,  in  consequence  of  the  abortion  or  obliteration  of  parts. 
Thus,  the  ovary  of  the  Oak  consists  of  three  cells,  with  a  pair  of 
ovules  in  each ;  but  the  acorn,  or  ripened  fruit,  presents  a  single 
cell,  filled  with  a  solitary  seed.  In  this  case,  only  one  ovule  is 
matured,  and  two  cells  and  five  ovules  are  suppressed.  The  ovary 
of  the  Horsechestnut  and  Buckeye  is  similar  in  structure  (Fig. 
777  -  780),  and  seldom  ripens  more  than  one  or  two  seeds  ;  but  the 
abortive  seeds  and  cells  may  be  detected  in  the  ripe  fruit.  The 
ovary  of  the  Birch  and  of  the  Elm  is  two-celled,  with  a  single  ovule 
in  each  cell :  the  fruit  is  one-celled,  with  a  solitary  seed ;  one  of  the 
ovules  or  young  seeds  being  uniformly  abortive,  while  the  other  in 
enlarging  thrusts  the  dissepiment  to  one  side,  so  as  gradually  to  ob- 
literate the  empty  cell ;  and  similar  instances  of  suppression  in  the 
fruit  of  parts  actually  extant  in  the  ovary  are  not  uncommon.  On 
the  other  hand,  there  are  sometimes  more  cells  in  the  fruit  than 
properly  belong  to  the  pistil.  For  instance,  the  ovary  of  Datura 
Stramonium  is  two-celled ;  but  the  fruit  soon  becomes  spuriously 
four-celled  by  a  false  partition  connecting  each  placenta  with  the 
dorsal  suture.  So  the  compound  ovary  of  Flax  when  young  is  five- 
celled,  but  with  a  strong  projection  from  the  back  of  each  cell  (Fig. 
500)  which  at  maturity  divides  the  cell  into  two,  thus  rendering 
the  fruit  ten-celled.  And  some  legumes  are  divided  transversely 
into  several  cells,  although  the  ovary  was  one-celled  with  a  continu- 
ous cavity  in  the  flower. 


310  THE    FRUIT. 

587.  Ripening.  The  pericarp  sometimes  remains  herbaceous  in 
texture,  like  the  pea-pod,  or  becomes  thin,  dry,  and  membranaceous, 
like  the  pod  of  the  Bladder-Senna.  In  such  cases  it  is  furnished 
with  stomates,  continues  to  have  chlorophyll  in  its  cells,  and  acts 
upon  the  air  like  an  ordinary  leaf.  In  other  plants  the  pericarp 
thickens,  and  either  becomes  hard  and  dry,  like  a  nut,  or  else  fleshy 
or  pulpy,  like  a  berry  (gooseberry,  grape,  &c.).  Sometimes  the 
outer  portion  softens  into  flesh  or  pulp,  while  the  inner  portion  hard- 
ens, thus  forming  a  stone-fruit,  like  the  cherry  and  peach. 

587'.  Most  fleshy  or  pulpy  fruits  are  tasteless  or  slightly  bitter 
during  their  early  growth ;  at  which  period  their  structure  and 
chemical  composition  are  similar  to  that  of  leaves,  consisting  of  cel- 
lular with  some  woody  tissue  ;  and  their  action  upon  the  atmosphere 
is  likewise  the  same  (346).  In  their  second  stage,  they  become 
sour,  from  the  production  of  acids  (353)  ;  such  as  tartaric  acid  in 
the  grape  ;  the  citric,  in  the  lemon,  orange,  and  the  cranberry ;  the 
malic,  in  the  apple,  gooseberry,  &c.  At  this  period  they  exhale  very 
little  oxygen,  or  even  absorb  that  substance  from  the  surrounding 
air.  The  acid  increases  until  the  fruit  begins  to  ripen,  when  it  grad- 
ually diminishes,  and  sugar  is  formed.  In  the  third  stage,  or  that  of 
ripening,  the  acids,  as  well  as  the  fibrous  and  cellular  tissues,  gradu- 
ally diminish  as  the  quantity  of  sugar  increases  ;  the  latter  being 
produced  partly  at  the  expense  of  the  former.  A  chemical  change, 
similar  to  that  of  ripening,  takes  place  when  the  green  fruits  are 
cooked ;  the  acid  and  the  mucilaginous  or  other  products,  by  the  aid 
of  heat  reacting  upon  each  other,  are  both  converted  into  sugar. 
Mingled  with  the  saccharine  matter,  a  large  quantity  of  vegetable 
jelly  (83)  is  also  produced  in  most  acidulated  pulpy  fruits,  ex- 
isting in  the  form  of  pectine  and  pectic  acid.  These  arise  from 
the  reaction  of  the  vegetable  acids  during  ripening  upon  the  dex- 
trine and  other  ternary   products   accumulated  in  the  fruit. 

588.  When  the  walls  of  a  pericarp  form  two  or  more  layers  of 
dissimilar  texture,  the  outer  layer  is  called  the  Fspicarp,  the  middle 
one,  Mesocarp,  and  the  innermost,  Endocarp.  A  stone-fruit  or 
drupe,  like  the  peach,  consists  of  two  layers,  viz.  the  outer  or  fleshy 
layer,  which  is  therefore  termed  the  Sarcocarp,  and  the  inner,  or 
endocarp,  the  shell  or  stone,  which  is  also  termed  the  Putamen. 

589.  Fruits  also  may  be  divided  into  the  indehiscent  or  closed,  and 
the  dehiscent  or  those  that  open.  Fleshy  fruits  generally,  stone- 
fruits,  and  many  dxy  fruits,  especially  one-seeded  ones,  such  as  nuts, 


ITS    KINDS.  311 

achenia,  &c,  remain  indehiscent ;  while  most  pods  or  capsules  dehisce 
at  maturity. 

590.  Some  pods  burst  irregularly  when  ripe  and  dry  ;  others  open 
and  shed  their  seeds  by  definite  pores,  as  the  Poppy,  or  by  larger 
holes,  chinks,  or  valves,  as  the  Campanula,  Snapdragon,  &c. ;  or  by 
a  transverse  line  cutting  off  the  top  of  the  pod,  as  in  Henbane  and 
Purslane.     These  are  modes  of  irregular  dehiscence.     But 

591.  Dehiscence,  when  regular  and  normal,  is  effected  by  a  vertical 
separation  or  splitting,  viz.  by  the  oj)ening  of  one  or  both  sutures  of  the 
ovary  (543),  or,  in  a  fruit  resulting  from  a  compound  ovary  (548), 
by  the  disjunction  of  the  united  parts.  The  several  modes  of  dehis- 
cence will  be  characterized  under  the  kinds  of  fruit  in  which  they 
occur  (607-614). 


Sect.  II.     The  Kinds  of  Fruit. 

592.  The  various  kinds  of  fruits  have  been  minutely  classified 
and  named  ;  but  the  terms  in  ordinary  use  are  not  very  numerous. 
A  rigorously  exact  and  particular  classification,  discriminating  be- 
tween the  fruits  derived  from  simple  and  from  compound  pistils,  or 
between  those  with  and  without  an  adnate  calyx,  becomes  too  recon- 
dite and  technical  for  practical  purposes.  It  is  neither  convenient 
nor  philosophical  to  give  a  substantive  name  to  every  variation  of 
the  same  organ.  For  all  ordinary  purposes  it  will  suffice  to  char- 
acterize the  principal  kinds  under  the  four  classes  of  Simp>le,  Aggre- 
gate, Accessory  or  Anthocarpous,  and  Multiple  Fruits. 

593.  Simple  Fl'UitS  are  those  which  result  from  the  ripening  of  a 
single  pistil,  whether  Avith  or  without  a  calyx  or  other  parts  adnate 
to  it.  This  division  comprises  most  of  the  kinds  of  fruit  which  have 
distinctive  names,  and  those  of  the  other  classes  are  mainly  aggre- 
gations or  combinations  of  these. 

594.  Simple  Fruits  may  be  conveniently  divided  into  Fleshy 
fruits,  Stone  fruits,  and  Dry  fruits.  The  leading  kind  of  the 
first  division  is 

595.  The  Berry  (Bacca),  an  indehiscent  fruit  which  is  fleshy  or 
pulpy  throughout.  The  grape,  gooseberry,  currant,  cranberry,  and 
tomato  are  familiar  examples. 

596.  The  Ilesperidium  (orange,  lemon,  and  lime)  is  merely  a  berry 
with  a  leathery  rind. 


312 


THE    FRUIT. 


597.  TllC  Pepo,  or  Goiird-frilit,  is  also  a  modification  of  the  berry, 
with  a  hard  rind,  which  occurs  in  the  Gourd  family.  The  cucum- 
ber, melon,  and  squash  are  familiar  illustrations.  A  Pepo  is  an 
indehiscent,  externally  firm  and  internally  pulpy  fruit,  composed 
usually  of  three  carpels,  and  with  an  adnate  calyx.  In  the  ovary  it 
is  either  one-celled  with  three  broad  and  revolute  parietal  placentas, 
or  these  placenta?,  borne  on  slender  dissepiments,  meet  in  the  axis, 
enlarge,  and  spread,  unite  with  their  fellows  on  each  side,  and  are 
reflected  to  the  walls  of  the  pericarp,  next  which  they  bear  their 
ovules    (Fig.   560,  561).     As  the  fruit  enlarges,  the  seed-bearing 

placentas  usually  cohere  with  the 
walls,  and  the  partitions  are  oblit- 
erated, giving  the  appearance  of 
a  peculiar  abnormal  placentation, 
which  only  the  study  of  the  ovary 
readily  explains. 

598.  A  Pome,  such  as  the  apple, 
pear,  and  quince  (Fig.  809,  812), 
is  a  fruit  composed  of  two  or  more 
carpels,  either  papery,  cartilagi- 
nous, or  bony,  usually  more  or  less 
involved  in  a  pulpy  expansion  of 
the  receptacle  or  disk,  and  the 
whole  invested  by  the  thickened  and  succulent  tube  of  the  calyx. 
It  may  be  readily  understood  by  comparing  a  rose-hip  with  an  apple. 
The  calyx  makes  the  princi- 
pal thickness  of  the  flesh  of 
the  apple,  and  the  whole  of 
that  of  the  quince. 

599.  Tlic    Drupe,   or   Stonc- 

Frilit,  is  a  one-celled,  one  or 
two  seeded  indehiscent  fruit, 
with  the  inner  part  of  the  peri- 
carp (endocarp,  or  putamen, 
588)  hard  or  bony,  while  the  outer  (exocarp,ov  sorcocarp)  is  fleshy 
or  pulpy  It  is  the  latter  which  in  these  fruits  so  readily  takes 
an  increased  development   in   cultivation.      The   name  is   strictly 

FIG.  560.     Section  of  the  ovary  of  the  Gourd.   561.  Diagram  of  one  of  its  constituent  carpels. 

FIG.  562.  A'ertical  section  of  a  peach.  563.  An  almond ;  where  the  exocarp,  the  portion 
of  the  pericarp  that  represents  the  pulp  of  the  peach,  remains  thin  and  juiceless,  and  at 
leDgth  separates  by  dehiscence  from  the  endocarp,  or  shell. 


ITS    KINDS. 


313 


applicable  only  to  fruits  produced  by  the  ripening  of  a  one-celled 
pistil;  as  the  plum,  peach  (Fig.  562),  &c. ;  but  it  is  extended  in  a 
general  way  to  such  fruits  with  two  or  more  bony  564 

cells  enclosed  in  pulp,  as  that  of  the  Dogwood,  &c. 

600.  The  raspberry  and  blackberry  (Fig.  564) 
are  composed  of  a  great  number  of  miniature  stone- 
fruits,  or  drupelets,  as  they  might  be  called,  in  struc- 
ture resembling  cherries  (Fig.  5G5),  aggregated  upon 
an  elongated  receptacle. 

601.  Dry  Fruits  may  be  either  dehiscent  or  indehis- 
cent  (589).  Of  indehiscent  dry  fruits  one  of  the 
simplest  kinds  is 

602.  The  Achenium,  or  Akene  (Fig.  566-573). 
This  includes  all  one- 
seeded,  dry  and  hard, 
indehiscent  and  seed- 
like, small  fruits,  such  as 
are  popularly  taken  for 
naked  seeds.  But  that 
they  are  true  pistils  or  566 

ovaries  ripened  is  evident  from  the  styles  or  stigmas  they  bear,  or 
from  the  scar  left  by  their  fall ;  and  a 
section  brings  to  view  the  seed  within, 
provided  with  its  own  proper  integuments. 
The  name  has  been  restricted  to  the  seed- 
like fruits  of  simple  pistils,  as  those  of 
the  Buttercup  (Fig.  566,  567),  Anemone, 
Clematis,  and  Geum  (where  the  persist- 


FIG.  564.  Magnified  vertical  section  of  half  of  a  blackberry.  565.  Section  of  one  of  the 
grains,  or  drupekts,  more  magnified. 

FIG.  566.  Achenium  of  a  common  Buttercup,  enlarged.  567.  Vertical  section  of  the  same, 
showing  the  seed  within. 

FIG.  568.  Achenium  of  Mayweed  (no  pappus).  569.  That  of  Cichory  (its  pappus  a  shal- 
low cup).  570.  Of  Sunflower  (pappus  of  two  deciduous  scales).  571.  Of  Sneczeweed  (Hele- 
nium),  with  its  pappus  of  five  scales.  572.  Of  Sow-Thistle,  with  its  pappus  of  delicate  downy 
hairs.    573.  Of  the  Dandelion,  its  pappus  raised  on  a  long  beak. 

27 


314 


THE   FRUIT. 


ent  style  usually  remains  on  the  fruit  as  a  long  tail),  and  the  minute 
grains  of  the  strawberry  (Fig.  559).  But  it  may  be  extended,  as 
is  now  generally  done,  to  all  such  one-celled  seed-like  fruits  result- 
ing from  a  compound  ovary,  and  even  when  invested  with  an  adnate 
calyx-tube.  Of  this  kind  is  the  fruit  of  all  Composite  (Fig.  568- 
573).  Here  the  tube  of  the  calyx  is  incorporated  with  the  surface 
of  the  ovary,  and  its  limb  or  border,  obsolete  in  some  cases  (Fig. 
568),  in  others  appears  as  a  crown  (Fig.  569),  cup,  a  set  of  teeth 
or  of  scales  (Fig.  570,  571),  or  as  a  tuft  of  bristles  or  hairs  (Fig. 
572,  573),  &c,  called  the  pappus.  In  the  Lettuce  and  Dandelion 
(Fig.  573),  the  achenium  is  rostrate,  i.  e.  its  summit  is  extended 
into  a  slender  beak. 

603.  A  Utricle  is  the  same  as  an  achenium,  only  with  a  thin  and 
bladdery  loose  pericarp,  like  that  of  Goosefoot  and 
Amaranth  (Fig.  574,  575).  The  thin  coat  commonly 
bursts  irregularly,  discharging  the  seed.  In  the  true 
Amaranths  it  opens  by  a  circular  line,  and  the  upper 
part  falls  as  a  lid,  converting  the  fruit  into  a  small 
pyxis  (619). 

604.  A  Caryopsis  or  Grain  differs  from  the  last  in  hav- 
ing the  seed  completely  filling  the  cell,  and  its  coat 
firmly  consolidated  throughout  with  the  very  thin  peri- 
carp, as  in  wheat,  Indian  corn,  and  other  cereal  grains 
(Fig.  622  -  624).  Of  all  fruits  this  is  the  kind  most 
likely  to  be  mistaken  for  a  seed. 

605.  A  Nut  is  a  hard,  one-celled  and  one-seeded,  indehiscent  fruit, 
like  an  achenium,  but  larger,  and  usually  produced 
from  an  ovary  of  two  or  more  cells  with  one  or  more 
ovules  in  each,  all  but  a  single  ovule  and  cell  having 
disappeared  during  its  growth  (586)  ;  as  in  the 
Hazel,  Beech,  Oak  (Fig.  576,  1166),  Chestnut, 
Cocoa-nut,  &c.  The  nut  is  often  enclosed  or  sur- 
rounded by  a  kind  of  involucre,  termed  a  Cupule  ; 
as  the  cup  at  the  base  of  the  acorn,  the  bur  of  the 
chestnut,  and  the  leaf-like  covering  of  the  hazel-nut. 

606.  A  Samara  or  Key-fruit  is  a  name  applied  to  a  nut,  or  achenium, 
having  a  winged  apex  or  margin ;  as  in  the  Birch,  Elm  (Fig.  578), 


FIG.  574.     Utricle  of  Chenopodium  album,  or  common  Goosefoot.    575.  Utricle,  or  pyxis, 
of  an  Amaranth. 
FIG.  576.    Acorn  (nut)  of  White  Oak,  with  its  cup  or  cupule. 


ITS    KINDS. 


315 


and  Ash  (Fig.  577).     The  fruit  of  the  Maple  consists  of  two  such 
fruits  belonging  to  one  flower,  united  by  their  bases  (Fig.  787). 

607.  Dehiscent  Fruits,  or  Pods,  are  distinguishable  into  a 
those  consisting  of  a  simple  pistil,  and  those  resulting         |}|jj|j| 
from  a  compound  pistil. 

608.  Of  those  originating  from  simple  pistils,  the 
principal  kinds  are  the  Follicle  and  the  Legume.  These 
may  be  taken  as  the  type,  of  simple  fruits. 

609.  A  Follicle  is  a  pod  formed  of  a  simple  pistil,  and 
dehiscent  by  the  ventral  or  inner  suture  alone  ;  as  in 

the  Milkweed,  Larkspur,  Columbine,  Peony, 
and  Marsh-Marigold  (Fig.  579).  "When  it 
opens  widely,  the  pistil  may  be  said  to  revert 
to  its  natural  state  of  a  leaf,  and  it  often  looks 
much  like  one,  as  in  Fig.  492. 

610.  A  Legume  is  a  pod  formed  by  the  ripen- 

579        ing  of  a  simple  pistil  which  dehisces  by  both 

sutures,  and  so  divides  into  two  valves  or  pieces,  as  in 

the  Bean  and  Pea  (Fig.  580).     This  being  the  ordinary 

fruit  of  the  Pulse  family,  accordingly  named 
Leguminosce  (or  Leguminous  plants),  the  name 
has  been  extended  to  it  in  descriptive  botany, 
in  all  cases,  whatever  the  form,  and  whether 
dehiscent  or  not.  The  legume  will  be  found 
to  exhibit  no  small  diversity  in  this  large  fam- 
ily (799).     Among  its  forms  is  one  termed 

611.  A  Loment.  This  is  a  legume  divided 
transversely  into  two  or  more  one-seeded  joints, 
which  usually  fall  apart  at  maturity  (Fig.  581). 
Commonly  these  joints  remain  closed,  as  in 
Desmodium ;  sometimes  they  split  into  two 
valves,  as  in  Mimosa. 

612.  A  Capsule  is  the  pod,  or  dehiscent  fruit, 
of  any  compound  pistil.  When  regularly  dehis- 
cent, as  already  stated  (591),  the  pod  splits 
lengthwise  into  pieces  or  valves. 

613.  A  capsule,  necessarily  consisting  of  two  or  more  carpels  or 

FIG.  577.  Samara  of  White  Ash.    578.  Samara  of  American  Elm. 

FIG.  579.  Follicle  of  Caltha  palustris,  the  Marsh-Marigold. 

FIG.  5S0.  Legume  of  a  Sweet  Pea,  already  dehiscent.     581.  Loment  of  a  Tick-Trefoil  or 
Desmodium. 


316 


THE    FRUIT. 


simple  pistils  united  into  one  body,  will  normally  dehisce  in  one 
of  two  ways.     Namely,  either  the  carpels  will  separate  at  the  line 
of  junction,  thus  resolving  the  pod  into  its  constituent 
elements ;  or  else,  these  parts  remaining  united,  each 
cell  will  open  on  the  back  by  a  splitting  of  the  dorsal 
suture.     The  former  constitutes 

614.  Septicidal  Dehiscence  (Fig.  582, 

584),  so  named  because  the  capsule  splits 
through  the  septa  or  partitions  (dissepi- 
ments), each  one  separating  into  its  two 
constituent  layers,  one  belonging  to  each 
carpel.  This  occurs  in  Azalea  and  its 
allies,  in  St.  Johnswort,  &c.  The  car- 
pels, thus  becoming  separate,  in  these 
cases  open  down  their  inner  suture, 
582  like  a  follicle,  and  discharge  the  seeds. 

When  the   cells   are   only  one-seeded,  after  separating  septicidally, 

they  often  remain   closed 

and  fall  away  separately, 

as  in  Mallow,  Vervain  (Fig. 

985),   &c.     Such  closed  or 

nearly  closed  cells  or  car- 
pels of  a  compound  pistil 

are  termed  cocci. 

615.  Loculicidal  Dehis- 
cence is  that  in  which  the  splitting  opens  into  the  loculaments  (in 
Latin,  locidi)  or  cells ;  that  is,  each  carpel  dehisces  by  its  dorsal 
suture  (Fig.  583,  585),  as  in  Iris,  the  Lily,  Hibiscus,  Evening  Prim- 
rose, &c.  The  dissepiments  here  are  necessarily  borne  on  the  mid- 
dle of  the  valves. 

616.  In  the  Violet,  &c.  we  have  the  loculicidal,  and  in  several 
kinds  of  St.  Johnswort  the  septicidal,  plan  of  dehiscence  in  one- 
celled  capsules ;  the  placenta?  (answering  to  the  partitions)  being 
borne  in  the  former  upon  the  middle  of  the  valves  ;  while  in  the 
latter  each  placenta  is  split  in  two,  and  one  half  borne  on  each  mar- 
gin of  a  valve. 


FIG.  582.    Dehiscent  capsule  of  Elodea,  enlarged,  showing  septicidal  dehiscence. 
FIG.  583.    Dehiscent  capsule  of  Iris,  showing  loculicidal  dehiscence ;  the  lower  part  cut 
across,  showing  the  dissepiments  borne  on  the  middle  of  the  valves. 
FIG.  584.    Diagram  (in  cross-section)  of  septicidal,  and,  585,  of  loculicidal,  dehiscence. 


ITS    KINDS. 


317 


617.  Septifragal  Dehiscence  is  a  modification  of  either  the  loculicidal 
or  the  septicidal,  in  which  the  valves  fall  away,  leaving  the  dissepi- 
ments behind  attached  to  the 

axis.  Fig.  586  is  a  diagram 
representing  this  in  a  case 
of  loculicidal  opening.  Fig. 
587,  from  the  common  Morn- 
ing-Glory, is  this  modifica- 
tion of  the  septicidal  mode. 

618.  Instead  of  splitting 

into  separate  pieces,  the  sutures  of  the  pericarp  sometimes  open  for 
a  short  distance  at  their  apex  only,  as  in  Cerastium  and  some  other 
Chickweeds,  in  Tobacco  (Fig.  1050),  and  in  the  Primrose  (Fig. 
943)  ;  or  by  mere  pores,  as  in  the  Poppy.  The  pod  of  the  Snap- 
dragon opens  by  the  bursting  of  a  hole  towards  the  top  of  each  cell, 
not  corresponding,  perhaps,  with  any  suture.  Another  anomalous 
mode  of  dehiscence,  namely,  the  circu??icissile,  characterizes 

619.  The  Pyxis  or  Pyxidium,  a  pod  which  opens  by  a  circular  hor- 

izontal line  cutting  off  the  upper  part  as  a  lid.  The 
fruits  of  the  Plantain,  Henbane,  Amaranth  (Fig. 
575,  which  is  otherwise  a  utricle),  Pimpernel,  and 
Purslane  (Fig.  588)  are  of  this  kind. 

620.  A  Silique  is  a  slender  two-valved  capsule,  with 
two  parietal  placentae,  from  which  the 
valves  separate  in  dehiscence ;  as  in 
plants  of  the  Cruciferous  or  Mustard 
family  (Fig.  589),  to  the  fruit  of  which  the  term  prop- 
erly belongs.  Usually  a  false  partition  is  stretched 
across  between  the  two  placenta3,  rendering  the  pod 
two-celled  in  an  anomalous  manner. 

621.  A  Silicle  or  Pouch  is  merely  a  short  silique,  its 
length  not  more  than  twice  its  breadth  ;  as  that  of  Shep- 
herd's-Purse,  Candytuft,  &c. 

622.  Aggregate  Fruits  are  those  in  which  a  cluster  of 
carpels,  all  belonging  to  one  flower,  are  crowded  on  the 
receptacle  into  one  mass,  as  in  the  raspberry  and  .blackberry  taken 
as  a  whole  (Fig.  564),  where  the  constituent  fruits,  or  ripened  carpels, 


FIG.  5S6.     Septifragal  modification  of  loculicidal,  and.  5S7,  of  septicidal,  dehiscence. 
FIG.  5S8.     Pyxis  or  pod  of  Purslane,  the  top  separating  as  a  lid. 
FIG.  5S9.     Silique  of  Cardamiue,  in  dehiscence. 

27* 


318  THE    FRUIT. 

are  little  drupes  ;  also  the  cone-like  fleshy  fruit  of  Magnolia,  where 
the  component  carpels  are  a  sort  of  drupaceous  follicles,  at  length 
opening  on  the  back  and  summit ;  and  the  dry  cone  of  the  Tulip-tree, 
where  each  carpel  forms  a  sort  of  samara.  None  of  these  aggregate 
fruits  have  special  names  in  ordinary  use.  In  descriptive  botany  it 
is  sufficient  to  state  the  kind  of  fruit  the  carpels  themselves  form, 
and  their  mode  or  degree  of  aggregation. 

623.  Accessory  or  Antliocarpous  Fruits  are  those  of  which  the  most 

conspicuous  portion,  although  often  appearing  like  a  pericarp,  neither 
belongs  to  the  pistil  nor  is  organically  united  Avith  it.  The  apparent 
berry  of  Gaultheria,  in  which  a  succulent  free  calyx  invests  a  dry 
pod  and  appears  to  form  the  real  fruit  (Fig.  912-914)  has  already 
been  adverted  to  (583)  ;  and  the  calyx  of  Shepherdia  is  similar, 
forming  what  appears  to  be  the  sarcocarp  of  a  drupe,  although  it  is 
really  free  from  the  achenium  it  encloses.  So,  also,  the  apparent 
achenium  or  nut  of  Mirabilis,  or  Four-o'clock,  is  the  thickened  and 
indurated  base  of  the  tube  of  a  free  calyx,  which  contracts  at  the 
apex  and  encloses  the  true  pericarp  as  a  utricle  or  thin  achenium, 
but  does  not  cohere  with  it.  The  rose-hip,  a  hollow  calyx-tube 
lined  with  a  hollow  receptacle  (Fig.  429),  and  the  strawberry  (Fig. 
428,  558,  559),  consisting  of  a  conical  enlarged  receptacle  bearing 
many  minute  achenia,  may  also  be  regarded  as  forms  of  antliocar- 
pous fruit. 

G24.  Multiple  Or  Collective  Fruits  are  those  which  result  from  the 
aggregation  of  several  flowers  into  one  mass.  The  simplest  of  these 
are  those  of  the  Partridge-Berry  (Mitchella)  and  of  some  species  of 
Honeysuckle  (Fig.  859),  consisting  of  the  ovaries  of  two  blossoms 
united  into  one  double  berry.  The  more  usual  sorts  are  such  as  the 
pine-apple,  mulberry,  and  the  fig.  These  are,  in  fact,  dense  forms 
of  inflorescence,  with  the  fruits  or  floral  envelopes  matted  together 
or  coherent  with  each  other ;  and  all  or  some  of  the  parts  become 
succulent.  The  grains  of  the  mulberry  (Fig.  593,  594)  are  not  the 
ovaries  of  a  single  flower,  like  those  of  the  blackberry  which  it  super- 
ficially resembles  (Fig.  564),  but  belong  to  as  many  separate  flow- 
ers ;  and  the  pulp  of  these  pertains  to  the  floral  envelopes  instead  of 
the  pericarp.  So  that  the  mulberry  is  an  anthocarpous  (623)  as 
well  as  a  multiple  fruit.  The  pine-apple  is  very  similar ;  only  the 
ovaries  or  pericarps  never  ripen  any  seeds,  but  all  are  blended,  with 
the  floral  envelopes,  the  bracts,  and  the  axis  of  the  stem  they  thickly 
cover,  into  one  fleshy  and  juicy  mass.     The  fig  (Fig.  590 -592) 


ITS    KINDS. 


319 


differs  from  the  pine-apple  in  having  this  succulent  axis  or  receptacle 

591  590  593 


on  the  outside.  It  may  be  compared  with  such  an  anthocarpous 
fruit  as  a  rose-hip  (Fig.  429).  It  results  from  a  multitude  of  flow- 
ers concealed  in  a  hollow  flower-stalk,  if  it 
may  be  so  called,  which  becomes  pulpy  and 
edible  when  ripe  ;  and  thus  the  fruit  seems 
to  grow  directly  from  the  axil  of  a  leaf, 
without  being  preceded  by  a  blossom.  The 
minute  flowers  concealed  within,  or  some  of 
them,  ripen  their  ova- 
ries into  very  small 
achenia,  which  are 
commonly  taken  for 
seeds.  The  principal 
form  of  multiple  fruit 
which  has  received  a 
substantive  name  is 
625.  The  Strobile  or  Cone,  a  scaly  multiple  fruit,  resulting  from  the 

FIG.  590-  A  young  fig.  591.  Vertical  section  of  the  same,  enlarged.  592.  A  small  slice  of 
the  same,  more  magnified,  showing  the  flowers  on  the  inside. 

FIG.  593.  A  young  mulberry.  594.  One  of  the  grains,  magnified,  showing  it  to  be  a  pis- 
tillate flower,  with  a  succulent  calyx  embracing  the  ovary  595.  The  same,  less  magnified,  the 
succulent  calyx  cut  away. 

FIG.  596.  Strobile  or  Cone  of  a  Pitch  Pine,  Pinus  rigida.  597.  Inside  view  of  one  of  the 
scales,  showing  one  of  the  seeds,  and  the  place  from  which  the  other,  598,  has  been  detached. 


320  THE    SEKD. 

ripening  of  some  sort  of  catkin.  The  name  is  applied  to  the  fruit  of 
the  Hop,  where  the  large  and  thin  scales  are  bracts  ;  but  it  more 
especially  belongs  to  the  Pine  or  Fir  cone,  the  peculiar  fruit  of  Co- 
nifera  (Fig.  596),  the  scales  of  which  are  open  carpels  (560),  bear- 
ing two  or  more  naked  seeds  upon  their  upper  or  inner  face  (Fig. 
597).  A  more  or  less  fleshy  and  closed  cone,  such  as  that  of  Taxo- 
dium,  and  especially  that  of  Juniper  (Savin,  Red  Cedar,  &c),  which 
at  maturity  imitates  a  berry,  has  been  termed  a  Galbalus. 


CHAPTER     XI. 

OF   THE   SEED. 
Sect.  I.     Its  Structure  and  Parts. 

626.  The  Seed,  like  the  ovule  (561),  of  which  it  is  the  fertilized 
and  matured  state,  consists  of  a  Nucleus,  or  kernel,  usually  en- 
closed within  two  Integuments. 

627.  Its  Integuments,  &C-  The  outer,  or 
proper  seed-coat,  corresponding  to  the  ex- 
terior coat  of  the  ovule,  is  variously  termed 
the  Epispeem,  Spermoderm,  or  more  com- 
monly the  Testa  (Fig.  599,  b).  It  varies 
greatly  in  texture,  from  membranaceous  or 
papery  to  crustaceous  or  bony  (as  in  the 
Papaw,  Nutmeg,  &c),  and  also  in  form,  being  sometimes  closely 
applied  (conformed)  to  the  nucleus,  and  in  other  cases  loose  and 
cellular  (as  in  Pyrola,  Fig.  927,  and  Sullivantia,  Fig.  843),  or  ex- 
panded into  wings  (as  in  the  Catalpa  and  Trumpet-Creeper,  Fig. 
601),  which  render  the  seeds  buoyant,  and  facilitate  their  dispersion 
by  the  wind  ;  whence  winged  seeds  are  only  met  with  in  dehiscent 
fruits.  The  wing  of  the  seed  of  Pines  (Fig.  598)  is  a  part  of  the 
surface  of  the  scale  or  carpel  to  which  it  is  attached,  and  which 
separates  with  it.     For  the  same  purpose,  the  testa  is  sometimes 

FIG.  599.  Vertical  magnified  section  of  the  (anatropous)  seed  of  the  American  Linden  :  a. 
the  hilum  ;  b,  the  testa  ;  c ,  the  tegmen  ;  d,  the  albumen ;  e,  the  embryo.  600.  Vertical  section 
of  the  (orthotropous)  seed  of  Ilelianthemum  Canadense :  a,  the  funiculus. 


ITS    STRUCTURE    AND    PARTS.  321 

provided  with  a  tuft  of  hairs  at  one  end,  termed  a  Coma  ;  as  in 
Epilobium  and  Milkweed  (Fig.  602).  In  the  Cotton-plant,  the 
whole  surface  of  the  seed  is  covered  with  long  wool. 
It  should  likewise  be  noticed,  that  the  integument  of 
numerous  small  seeds  is  furnished  with  a 
coating  of  small  hairs  containing  spiral 
threads  (one  form  of  which  is  represented 
in  Fig.  44),  and  usually  appressed  and  con- 
fined to  the  surface  by  a  film  of  mucilage. 
"When  the  seed  is  moistened,  the  mucilage 
softens,  and  these  hairs  spread  in  every 
direction.  They  are  often  ruptured,  and 
the  extremely  attenuated  elastic  threads  they  contain  uncoil,  and  are 
protruded  in  the  greatest  abundance  and  to  a  very  considerable  length. 
This  minute  mechanism  subserves  an  obvious  purpose  in  fixing 
these  small  seeds  to  the  moist  soil  upon  which  they  lodge,  when  dis- 
persed by  the  wind.  Under  the  microscope,  these  threads  may  be 
observed  on  the  seeds  of  most  Polemoniaeeous  plants,  and  on  the 
achenia  of  Labiate  and  Composite  plants,  as,  for  example,  in  many 
species  of  Senecio,  or  Groundsel.  In  Peony  the  testa  becomes 
fleshy  or  baccate ;  in  Magnolia  it  imitates  a  drupe. 

628.  The  inner  integument  of  the  seed,  called  the  Tegmen  or 
Exdopleura,  although  frequently  very  obvious  (as  in  Fig.  599,  c), 
is  often  indistinguishable  from  its  being  coherent  with  the  testa,  and 
is  sometimes  altogether  wanting. 

629.  The  stalk  of  the  seed,  as  of  the  ovule,  is  called  the  Fu- 
niculus (Fig.  600,  a).  The  scar  left  on  the  face  of  the  seed,  by  its 
separation  from  the  funiculus  at  maturity,  is  termed  the  Hil-um. 
The  chalaza  and  rhaphe,  when  present,  are  commonly  obvious  in 
the  mature  seed,  as  well  as  in  the  ovule  (564-568),  and  the  name 
and  relations  of  these  several  parts  in  the  seed  are  the  same  as  in 
the  ovule.  Also  the  terms  orthotropous,  anatropous,  eampylotrojious, 
&c,  originally  applied  to  the  ovules,  are  extended  to  the  seeds  which 
result  from  them ;  so  that  we  may  say,  Seeds  anatropous,  as  well  as 
Ovules  anatropous,  &c. 

630.  Aril  or  Al'illus.  Some  seeds  are  furnished  with  a  covering, 
(usually  incomplete  and  of  a  fleshy  texture,)  wholly  exterior  to  their 
proper  integuments,  arising  from  an  expansion  of  the  apex  of  the 

FIG.  601.     The  winged  peed  of  Trumpet-Creeper. 

FIG.  602.     Seed  of  Milkweed  (Asclepias  Coruuti),  with  its  coma  or  tuft. 


322  THE    SEED. 

seed-stalk,  or  funiculus,  or  of  the  placenta  itself  when  there  is  no 
manifest  seed-stalk.  This  is  called  the  Aril.  It  forms  the  pulpy 
envelope  of  the  seed  of  Podophyllum,  Euonymus,  and  Ce- 
lastrus,  or  it  appears  as  a  mere  lateral  scale  in  Turnera,  or 
as  a  tough  and  lacerated  body,  known  by  the  name  of  mace, 
in  the  Nutmeg.  In  the  White  Water-Lily  it  is  a  thin  and 
delicate  cellular  bag,  open  at  the  end  (Fig.  G03).  The 
Aril  does  not  appear  in  the  ovule,  but  is  developed  subse- 
603  quent  to  fertilization,  during  the  growth  of  the  seed.  Of 
the  same  or  similar  nature  is  the  Caruncle  found  at  the  hilum  in 
Polygala,  forming  a  loose  lateral  appendage.  Strictly  speaking,  it 
is  to  be  distinguished  from  the  Strophiole  (like  that  of  Euphor- 
bia), which  is  a  cellular  growth  from  the  micropyle ;  but  the  two  are 
not  well  discriminated.  An  analogous  cellular  growth  takes  place 
on  the  rhaphe  of  the  Bloodroot,  of  the  Prickly  Poppy,  and  of  Dicen- 
tra,  forming  a  conspicuous  crest  on  the  whole  side  of  the  seed. 

631.  The  Nucleus,  or  Kernel  of  the  seed,  consists  of  the  Albumen, 
when  this  substance  is  present,  and  the  Embryo. 

632.  The  Albumen,  which  has  also  been  termed  the  Perisperm  or 
the  Endosperm,  has  already  been  described  (125)  as  the  floury  part 
of  those  seeds  in  which  an  amount  of  nourishment  for  the  germi- 
nating plantlet  is  stored  up  outside  of  the  embryo.  This  was 
called  by  Gartner  the  albumen  of  the  seed,  from  some  fancied  anal- 
ogy with  the  white  of  an  egg  as  to  situation  or  function  ;  —  an  un- 
fortunate term,  on  account  of  its  liability  to  be  confounded  with  the 
quaternary  chemical  substance  of  the  same  name  (357),  one  of  the 
forms  of  proteine.  Being  in  general  use,  the  term  cannot  now  well 
be  discarded. 

633.  The  Albumen  of  the  seed  consists  of  whatever  portion  of  the 
tissue  of  the  ovule  persists,  and  becomes  loaded  with  nutritive  mat- 
ter accumulated  in  its  cells,  —  sometimes  in  the  form  of  starch- 
grains  principally,  as  in  wheat  and  the  other  cereal  grains ;  some- 
times as  a  continuous,  often  dense,  incrusting  deposit,  as  in  the  cocoa- 
nut,  the  date,  the  coffee-grain,  &c.  When  it  consists  chiefly  of 
starch-grains,  and  may  readily  be  broken  down  into  a  powder,  it  is 
said  to  be  farinaceous,  or  mealy,  as  in  the  cereal  grains  generally,  in 
buckwheat,  &c  When  a  fixed  oil  is  largely  mixed  with  this,  it 
becomes  oily,  as  in  the  seed  of  the  Poppy,  &c. ;  when  more  compact, 
but  still  capable  of  being  readily  cut  with  a  knife,  it  isjles/iy,  as  in 

FIG.  603.     A  seed  of  the  White  Water-Lily,  with  its  sac-like  arillus,  magnified. 


THK  ALBUMKN  AND  EMBRYO. 


323 


the  Barberry,  &c. ;  when  it  chiefly  consists  of  mucilage  or  vegetable 
jelly,  as  in  the  Morning-Glory  and  the  Mallow,  it  is  said  to  be  muci- 
laginous ;  when  it  hardens  more,  and  becomes  dense  and  tough,  so 
as  to  offer  much  resistance  to  the  knife,  as  in  the  Coffee,  the  Blue 
Cohosh,  &c,  it  is  corneous,  that  is,  of  the  texture  of  horn.  Between 
these  all  gradations  occur.  Commonly  the  albumen  is  a  uniform 
deposit.  But  in  the  nutmeg,  as  also  in  the  seeds  of  the  Papaw  (Fig. 
658),  and  of  all  plants  of  the  Custard-Apple  Family,  it  presents  a 
wrinkled  or  variegated  appearance,  owing  to  numerous  transverse 
divisions,  which  are  probably  caused  by  inflections  of  the  innermost 
integument  of  the  seed :  in  these  cases  the  albumen  is  said  to  be  rumi- 
nated. The  albumen  may  originate  from  new  tissue  formed  either 
within  the  embryo-sac  (579),  which  is  probably  the  more  common 
case ;  or  in  the  nucleus  of  the  ovule  exterior  to  the  embryo-sac, 
which  is  certainly  the  case  in  the  Water-Lily  and  its  allies,  and  in 
Saururus ;  for  here  the  thickened  embryo-sac  persists  within  or  at 
one  extremity  of  the  copious  albumen  ;  or  both  kinds  may  coexist. 
When  this  is  the  case,  the  outer  albumen  may  be  distinguished  as  the 
perisperm,  and  the  inner  as  the  endosperm. 

G34.  Seeds  provided  with  albumen  (as  in  Fig.  599,  600,  605,  606, 
609,  610-616,  622,  &c.)  are  said  to  be  albuminous;  those  destitute 
of  it  (as  in  Fig.  607,  629,  110,  120,  &c.)  are  exalbuminous.  The 
comparative  amount  of  the  albumen,  and  its  relation  to  the  embryo 
in  various  seeds,  may  be  seen  on  inspection  of  many  of  the  subjoined 
figures. 


635.  The  Embryo,  or  Germ,  being  an  initial  plantlet  or  individual,  is 
of  course  the  most  important  part  of  the  seed :  to  its  production,  protec- 

FIG.  604.     Seed  of  a  Violet  (anatropous),  enlarged:  a,  hilum  or  scar  ;  b,  rhapbe  ;  c,  chalaza. 

FIG.  605.  Vertical  section  of  the  same,  showing  the  straight  embryo  in  the  axis  of  the  mealy- 
albumen. 

FIG.  606.  Vertical  section  of  the  (orthotropous)  seed  of  Buckwheat,  showing  the  embryo 
folded  round  in  the  mealy  albumen. 

FIG.  607.  Vertical  section  of  the  (anatropous)  seed  of  Elodea  Virginica,  the  embryo  com- 
pletely filling  the  coats. 

FIG.  608.  Seed  of  Delphinium  tricome  (anatropous),  enlarged  ;  a,  the  hilum  ;  b,  the 
rhapbe  ;  c,  the  chalaza.  609.  Vertical  section  of  the  same  :  c,  the  chalaza ;  d,  the  testa ;  e, 
the  tegmen  ;  /,  the  albumen  ;  g-,  the  minute  embryo  near  the  hilum,  a. 


324 


THE    SEED. 


tion,  and  support  all  the  other  parts  of  the  fruit  and  flower  are  sub- 
servient. It  becomes  a  plant  by  the  mere  development  of  its  parts  : 
it  therefore  possesses,  in  a  rudimentary  or  undeveloped  state,  all  the 
essential  organs  of  vegetation,  namely,  a  root,  stem,  and  leaves.  Its 
general  structure  and  development  have  already  been  explained  in 
considerable  detail  (118  -  130). 

G36.  In  albuminous  seeds  it  is  naturally  the  smaller  and  its  parts 

the  less  developed  in  proportion  to  the  amount  of  albumen,  and  the 

6io  612  en  6i6  several  organs  are 

developed  or  even 
formed  in  germina- 
tion. In  exalbumi- 
nous  seeds,  where 
the  embryo  con- 
stitutes the  whole 
kernel,  its  several 
parts  are  ordina- 
rily conspicuous, 
although  they  are 
often  more  or  less  disguised  by  thickening;  as  the  cotyledons  in 
the  Almond  (Fig.  108)  and  Cherry  (Fig.  Ill),  and  especially  in 
the  Pea  (Fig.  118),  the  Acorn  (Fig.  120),  the  Horsechestnut  (Fig. 
630),  and  the  like. 

637.  The  parts  of  the  embryo,  as  already  illus- 
trated (120)  are  the  Radicle,  the  Cotyledons,  and 
the  Plumule.  The  radicle  is  the  axis,  or  rudimen- 
tary stem,  —  the  first  internode  of  the  axis  (121, 
157),  from  the  lower  extremity  of  which  the  root 
is  produced,  while  the  other  bears  the  cotyledons, 
i.  e.  the  leaves  of  the  first  node  ;  and  the  plumule 
is  the  bud  which  crowns  the  summit  of  the  radicle. 

638.  Owing  to  the  mode  of  its  formation  (580),  the  radicle  of  the 


FIG.  610.  Vertical  section  of  the  seed  of  a  Peony,  showing  a  small  embryo  near  the  base  of 
the  copious  albumen.     611.  The  embryo,  detached,  and  more  magnified. 

FIG.  612.  Section  of  a  seed  of  Barberry,  with  a  straight  embryo  in  the  axis  of  the  albu- 
men.    613.  Its  embryo,  detached. 

FIG.  614.  Section  of  a  Potato-seed,  showing  the  embryo  coiled  in  the  albumen.  615.  Its 
embryo,  detached. 

FIG.  616.  Section  of  the  seed  of  Mirabilis  or  Four-o"clock,  showing  the  embryo  coiled  round 
the  outside  of  the  albumen.     617.  Its  embryo,  detached,  and  partly  spread  out. 

FIG.  618.  Embryo  of  the  Pumpkin,  with  its  short  radicle  and  large  and  flat  cotyledons, 
seen  flatwise.     619.  A  vertical  section  of  the  same,  viewed  edgewise. 


THE    EMBRYO. 


325 


embryo  is  always  near  to  and  points  towards  the  micropyle  of  the 
seed,  viz.  to  what  was  the  orifice  of  the  ovule;  and  if  the  embryo  be 
straight  (as  in  Fig.  605),  or  merely  partakes  of  the  curvature  of 
the  seed,  the  cotyledons  point  to  the  opposite  extremity  of  the  seed, 
that  is,  to  the  chalaza.  The  position  of  the  radicle  as  respects  the 
hilum  varies  with  the  different  kind  of  seed.  In  the  orthotropous 
form,  as  in  Helianthemum  (Fig.  600)  and  Buckwheat  (Fig.  606), 
the  radicle  necessarily  points  directly  away  from  the  hilum.  In  the 
anatropous  form,  as  in  the  seed  of  the  Lin- 
den (Fig.  599)  and  Violet  (Fig.  604,  605), 
the  extremity  of  the  radicle  is  brought  to 
the  immediate  vicinity  of  the  hilum ;  and 
so  it  is,  although  in  a  different  way  in 
the  campylotropous  seed  (Fig.  620,  621)  ;  while  in  the  amphitro- 
pous,  the  radicle  points  away  from  the  hilum  laterally,  at  a  right 
angle  to  the  funiculus.  As  the  nature  of  the  ovule  and  seed  may 
usually  be  ascertained  by  external  inspection,  so  therefore  the  situa- 
tion of  the  embryo  within,  and  of  its  parts,  may  often  be  inferred 
without  dissection.  But  the  dissection  of  seeds  is  not  generally  a 
difficult  operation. 

639.  The  position  of  the  embryo  as  respects  the  albumen,  when 
that  is  present,  is  various.  Although  more  commonly  in  the  axis,  it 
is  often  excentric,  or  even  external  to  the  albumen,  as  in  all  Grasses 
and  cereal  Grains  (Fig.  622-624),  in  Polygonum  (Fig.  1111),  &c. 
When  external  or  nearly  so,  and  curved  circularly  around  the  albu- 


men, as  in  Goosefoot,  Chickweed  (Fig.  621),  and  Mirabilis  (Fig. 
616),  it  is  said  to  be  peripheric.     When  bent  or  folded  in  such  a 

FIG.  620.     Campylotropous  seed  of  the  common  Chickweed  (Stellaria  media),  magnified. 

FIG.  621.     Section  of  the  same,  showing  the  embryo  coiled  around  the  outside  of  albumen. 

FIG.  622.  Vertical  section  of  a  grain  of  Indian  Corn,  passing  through  the  embryo  :  c,  the 
cotyledon  ;  p,  the  plumule  ;  r,  the  radicle.  (A  highly  magnified  portion  of  the  albumen,  which 
makes  up  the  principal  bulk  of  the  grain,  is  shown  in  Fig.  70,  p.  54.)  623.  Similar  section  of 
a  grain  of  Rice.  624.  Vertical  section  of  an  Oat-grain  :  a,  the  albumen  ;  c,  the  cotyledon  ;  p, 
the  plumule  ;  and  r,  the  radicle  of  the  embryo. 

28 


326  THE    SEED. 

way  that  the  radicle  lies  along  the  edges  of  the  cotyledons,  the 
latter  are  said  to  be  accumbent  (Fig.  700)  ;  or  when  the  radicle 
rests  against  the  back  of  one  of  them,  or  in  j:>roxirnity  to  it  (Fig. 
705),  they  are  incumbent. 

640.  The  direction  of  the  embryo  with  respect  to  the  pericarp  is 
also  particularly  noticed  by  systematic  writers ;  who  employ  the 
terms  ascending,  or  radicle  superior,  when  the  latter  points  to  the 
apex  of  the  fruit ;  descending,  or  radicle  inferior,  when  it  points  to 
its  base ;  centripetal,  when  the  radicle  is  turned  towards  the  axis 
of  the  fruit ;  centrifugal,  when  turned  towards  the  sides ;  and  vague, 
when  it  bears  no  evident  or  uniform  relation  of  the  kind  to  the 
pericarp. 

641.  As  to  the  number  of  its  cotyledons,  or  the  degree  of  com- 
plexity or  simplicity  of  the  embryo,  the  principal  types  have  already 
been  considered  (128).  The  plan  of  the  embryo  in  Exogenous 
plants  is  to  have  a  pair  of  opposite  cotyledons  ;  that  is,  the  embryo 
is  dicotyledonous,  and  such  plants  are  denominated  Dicotyledo- 
nous Plants. 

642.  A  modification  of  this  plan  occurs  in  Pines  and  most  other 
Coniferre,  in  which  the  cotyledons  are  increased  to  three,  four,  six, 
or  even  to  fifteen,  in  a  whorl  (Fig.  133,  134)  ;  and  this  embryo  of 
highest  complexity  is  called  polycotyledonous.  The  embryos  of 
some  Leguminous  or  Cruciferous  plants  are  occasionally  found,  with 
three  cotyledons,  as  an  accidental  deviation. 

643.  But  in  all  Endogenous  plants  only  one  cotyledon  appears, 
i.  e.  only  one  seed-leaf  on  the  primary  node ;  if  two  or  more  rudi- 
mentary leaves  are  present,  they  are  alternate,  and  all  but  the  first 

belong  to  the  plumule.     Here  the  em- 
bryo   is    monocotyledonoui,    and    hence 
%    I  \     /  \  Endogens  are  also  termed  Monocoty- 

ledonous  Plants.  The  monocoty- 
ledonous  embryo  does  not  usually  pre- 
sent a  manifest  distinction  into  radicle, 
v^  \_1/  cotyledons,  and  plumule,  as  the  dicoty- 
ledonous ;  but  often  appears  like  a  ho- 
mogeneous and  undivided  cylindrical  or  club-shaped  body,  as  in  Iris 

FIG.  625.  Seed  of  Triglochin  palustre ;  the  rhaphe,  leading  to  the  strong  chalaza  at  the 
eummit,  turned  towards  the  eye.  626.  The  embryo  detached  from  the  seed-coats,  showing 
the  longitudinal  chink  at  the  base  of  the  cotyledon  ;  the  short  part  below  is  the  radicle.  627. 
Same,  with  the  chink  turned  laterally,  and  half  the  cotyledon  cut  away,  bringing  to  view  the 
plumule  concealed  within.    628    A  cross-section  through  the  plumule,  more  magnified. 


THE    EMBRYO. 


327 


(Fig.  131)  and  Triglochin  (Fig.  626).  In  the  latter,  however,  close 
inspection  reveals  a  vertical  slit  or  chink  just  above  the  radicular 
extremity,  through  which  the  plumule  is  protruded  in  germination. 
If  the  embryo  be  divided  parallel  with  this  slit,  the  plumule  is 
brought  into  view  ;  as  in  Fig.  G27.  If  a  horizontal  section  be  made 
at  this  point  (as  in  Fig.  G28),  the  cotyledon  is  found  to  be  wrapped 
around  the  enclosed  plumule,  sheathing  it,  much  as  the  bud  and  the 
3-ounger  parts  of  the  stem  are  sheathed  by  the  bases  of  the  leaves 
in  most  monocotyledonous  plants.  The  plumule  is  more  manifest 
in  Grasses,  especially  in  the  cereal  grains,  and  more  complex,  ex- 
hibiting the  rudiments  of  several  concentric  leaves,  or  of  a  strong 
bud,  previous  to  germination  (Fig.  622-624,  and  126-128).  In 
many  cases,  however,  no  distinction  of  parts  is  apparent  until  ger- 
mination commences  ;  as  in  the  Onion,  Iris  (Fig.  131),  &c. 

G-44.  In  several  Dicotyledonous  plants  one  cotyledon  is  smaller 
than  the  other,  viz.  the  inner  one,  when  the  embryo  is  coiled  or 
folded.  And  in  all  the  species  of 
Abronia  this  cotyledon  is  wanting, 
so  that  the  embryo  becomes  tech- 
nically monocotyledonous.  In 
the  Dodder,  a  genus  of  leafless 
parasitic  plants  of  the  Convolvu- 
lus family,  the  embryo  also  is 
entirely  destitute  of  cotyledons 
(Fig.  148).  Here  these  organs 
are  suppressed  in  an  embryo  of 
considerable  size ;  but  in  most 
such  parasites,  the  embryo  is  very 
minute,  as  well  as  reduced  to  the 
greatest  degree  of  simplicity,  and 
seems  to  remain  until  germination 
in  a  very  rudimentary  state. 

645.  Sometimes  the  two  cotyle- 
dons of  a  dicotyledonous  embryo 
are  consolidated,  or  more  or  less 
coherent  by  their  contiguous  faces 

into  one  mass,  when  they  are  said  to  be  conferruminate,  as  in  the 
Horsechestnut,  Buckeye  (Fig.  629,  630),  and  the  Chestnut.  In 
these,  as  in  other  embryos  with  very  thick  cotyledons,  the  latter  are 

FIG.  629.     Section  of  the  seed  of  a  liuckeye.     630.  A  Buckeye  in  germination. 


328  THE    SEED. 

necessarily  hypogceous  in  germination  (124,  126),  that  is,  they  re- 
main underground,  enclosed  within  the  coats  of  the  seed,  yielding 
their  abundant  store  of  nourishment  to  the  radicle  and  the  plumule ; 
and  the  first  leaves  that  appear  are  those  of  the  plumule. 


Sect.  II.     Germination. 

646.  Germination  is  the  initial  act  of  growth,  by  which  the  embryo 
in  a  seed  develops  into  a  plantlet.  The  steps  of  the  early  growth 
have  already  been  sufficiently  explained  in  an  early  part  of  this  vol- 
ume (119-132). 

647.  The  seeds  of  some  plants  (such  as  the  Red  Maple)  germi- 
nate shortly  after  falling  to  the  ground ;  those  of  most  other  plants 
not  until  the  next  year,  or  even  later.  How  long  seeds  may  retain 
the  power  of  germinating  is  uncertain,  and  is  extremely  variable  in 
different  species  and  families.  Those  of  many  plants  under  ordinary 
circumstances  can  rarely  be  made  to  grow  after  two  or  three  years ; 
some  will  germinate  pretty  well  after  several  years  keeping ;  and 
the  seeds  of  certain  Leguminous  plants  have  been  known  to  germi- 
nate when  sixty  years  old.  But  the  current  accounts  of  wheat,  &c. 
being  raised  from  grain  taken  from  ancient  mummies,  circumstan- 
tially authenticated  as  some  of  them  appear  to  be,  must  be  received 
with  the  greatest  misgiving,  if  not  with  entire  incredulity.  One  of 
the  most  probable  cases  of  germination  of  ancient  seeds  on  record  is 
that  given  by  Dr.  Lindley,  of  some  Raspberries,  "  raised  in  the  gar- 
den of  the  Horticultural  Society  from  seeds  taken  from  the  stomach 
of  a  man,  whose  skeleton  was  found  thirty  feet  below  the  surface  of 
the  earth,  at  the  bottom  of  a  barrow  which  was  opened  near  Dorches- 
ter. He  had  been  buried  with  some  coins  of  the  Emperor  Hadrian ; 
and  it  is  therefore  probable  that  the  seeds  toere  sixteen  or  seventeen 
hundred  years  old."  Most  seeds,  when  buried  deep  in  the  soil, 
where  they  are  subject  to  a  uniform  and  moderate  temperature,  and 
removed  from  the  influence  of  the  air  and  light,  may  be  in  a  favorable 
state  for  the  preservation  of  vitality,  and  would  be  likely  to  germi- 
nate when  brought  to  the  surface  after  a  considerable  interval.  But 
the  possibility  of  mistake  or  of  collusion  must  be  more  thoroughly 
eliminated  before  a  case  of  such  extraordinary  tenacity  of  life,  under 
conditions  in  some  respects  very  unfavorable,  can  be  considered  as 
well  established. 


GERMINATION.  329 

648.  The  conditions  requisite  to  germination  are  exposure  to 
moisture  and  to  a  certain  amount  of  heat,  varying  from  50°  to  80° 
(Fahrenheit)  for  the  plants  of  temperate  climates,  to  which  must  be 
added  a  free  communication  with  the  air.  Direct  light,  so  essential 
to  subsequent  vegetation,  is  unnecessary,  and  generally  unfavorable, 
to  germination.  The  degree  of  heat  required  to  excite  the  latent 
vitality  of  the  embryo  is  nearly  uniform  in  the  same  species,  but 
widely  different  in  different  plants ;  since  the  common  Chickweed 
will  germinate  at  a  temperature  not  far  above  the  freezing-point  of 
water,  while  the  seeds  of  many  tropical  plants  require  a  heat  of 
90°  to  110°  (Fahrenheit)  to  call  them  into  action,  and  are  often 
exposed  to  a  considerably  higher  temperature.  Seeds  are  in  the 
most  favorable  condition  for  germination  in  spring  or  summer,  when 
loosely  covered  with  soil,  which  excludes  the  light  while  it  freely 
admits  the  air,  moistened  by  showers,  and  warmed  by  the  rajs  of 
the  sun.  The  water  which  is  slowly  absorbed  softens  all  parts  of 
the  seed ;  the  embryo  swells,  and  bursts  its  envelopes,  or  the  elon- 
gating radicle  is  protruded  from  them,  and  all  the  parts  grow  or 
unfold  in  the  manner  already  described,  each  organ  in  its  proper 
medium,  the  root  being  developed  in  the  soil,  and  the  stem  and 
leaves  in  the  air. 

649.  The  nourishment  which  the  embryo  requires  during  germi- 
nation is  furnished  by  the  starch,  &c.  of  the  albumen  (682),  when 
this  substance  is  present  in  the  seed ;  or  by  starchy  or  other  nutri- 
tive matter  accumulated  in  its  own  tissue  (636, 123).  But  as  starch 
is  insoluble  in  cold  water,  certain  chemical  changes  are  necessary  to 
bring  it  into  a  fluid  state,  so  that  it  may  nourish  the  embryo.  These 
changes  are  incited  by  the  proteine  or  neutral  azotized  products 
(354),  which  are  largely  accumulated  in  the  seed,  either  in  the 
albumen  or  in  the  embryo  itself,  and  which  take  the  initiative  in  all 
the  transformations  of  vegetable  matter  (27).  In  the  germinating 
seed,  just  as  in  growth  from  a  bulb  or  tuber,  the  changes  essentially 
consist  in  the  transformation  of  the  starch,  first  into  dextrine,  or 
gum,  and  thence  into  sugar,  a  part  of  which  is  destroyed  by  resolu- 
tion, first  into  acetic  acid,  and  finally  into  carbonic  acid  and  water, 
with  the  abstraction  of  oxygen  from  the  air,  and  the  evolution  of 
heat  (349,  370-373),  while  the  remainder  is  rendered  directly  sub- 
servient to  the  groAvth  of  the  plantlet.  The  reason  why  light,  so 
essential  to  subsequent  growth,  impedes  or  prevents  incipient  ger- 
mination, becomes  evident  when  we  remember  that  it  incites  the 

28* 


330  REPRODUCTION   IN 

decomposition  of  carbonic  acid,  and  the  fixation  of  carbon  by  the 
plant  (344  —  350)  ;  while  germination  is  necessarily  attended  by  an 
opposite  transformation,  namely,  the  destruction  of  a  portion  of  or- 
ganized matter,  with  the  evolution  of  carbonic  acid.*  In  germina- 
tion, as  in  any  other  act  in  which  matter  is  transformed  or  trans- 
ferred, there  is  a  certain  expenditure  of  force  and  loss  of  organized 
material.  The  plantlet  is  obliged  to  decompose  and  destroy  a  part 
of  the  starch  or  other  material  provided  for  its  initial  growth,  in 
order  that  it  may  transform  the  rest  into  dextrine  and  sugar,  and 
this  again  into  cellulose  or  the  material  of  the  new  cells  formed  in 
its  growth. 

650.  The  study  of  the  seed,  and  of  the  development  of  the  em- 
bryo it  contains  into  a  plantlet,  completes  the  cycle  of  A^egetable  life 
in  the  higher  grade  of  Phamogamous  plants,  and  brings  us  back  to 
our  starting-point  (118,  119). 


CHAPTER     XII. 

OF  REPRODUCTION  IN  CRYPTOGAMOUS  OR  FLOWERLESS  PLANTS. 
* 
651.  The  lower  grade  of  Cryptogamous  or  Flowerless 
Plants  (Chap.  II.  Sect.  I.)  would  now  require  to  be  considered, 
both  as  to  the  vegetation  and  their  reproduction.  But  the  plan  of 
structure  in  each  principal  Cryptogamous  family  is  so  peculiar, 
and  the  organs  of  fructification  especially  so  diverse,  that  their 
morphology  cannot  be  presented  under  one  common  type,  as  in  Pha?- 
nogamous  vegetation.  Each  great  family  or  group  would  have  to 
be  separately  treated,  and  with  much  fulness  of  illustration,  to  make 


*  Seeds  may  casually  germinate  while  attached  to  the  parent  plant,  especially 
such  as  arc  surrounded  with  pulp,  like  those  of  the  Cucumber  and  Melon.  The 
process  is  liable  to  commence  in  wheat  and  other  grain,  when  protracted  warm 
and  rainy  weather  occurs  at  the  period  of  ripening  ;  and  the  albumen  becomes 
glutinous  and  sweet,  from  the  partial  transformation  of  the  starch  into  dextrine 
and  sugar.  In  the  Mangrove,  which  forms  dense  thickets  along  tropical  coasts, 
germination  habitually  commences  in  the  pericarp  while  the  fruit  remains  on  the 
tree ;  and  the  radicle,  piercing  the  integuments  which  enclose  it,  elongates  in  the 
air ;  such  a  plant  being,  as  it  were,  viviparous. 


CRYPTOGAMOUS    OR    FLOWERLESS    PLANTS.  331 

the  subject  intelligible  to  tbe  unpractised  student.  This  can  hardly 
be  done  in  so  elementary  a  work  as  the  present,  but  requires  a  sepa- 
rate treatise.  The  student  who  has  intelligently  studied  the  present 
volume  up  to  the  present  point,  is  prepared  for  the  more  difficult  study 
of  the  structure  of  Cryptogamous  plants,  in  the  only  general  work  of 
the  kind  that  has  yet  appeared  in  the  English  language,  viz.  Berke- 
ley's Introduction  to  Cryptogamic  Botany.  An  enumeration  of  the 
Cryptogamous  orders,  with  a  brief  notice  of  their  structure  and  sub- 
ordinate divisions,  may  be  found  in  the  systematic  part  of  the  pres- 
ent work.  A  slight  sketch  of  their  grades  of  development  as  to 
vegetation  has  already  been  given  (97-113).  We  here  attempt 
to  present  merely  a  very  brief  and  general  account  of  their  plan  of 
reproduction,  divested  as  far  as  possible  of  technical  terms. 

652.  Taken  collectively,  we  distinguish  this  lower  series  of  the 
vegetable  kingdom  by  negative  characters  only ;  saying  that  these 
plants  do  not  bear  true  flowers  (consisting  essentially  of  stamens  and 
pistils),  and  accordingly  do  not  produce  seeds,  or  bodies  consisting 
of  a  distinguishable  embryo  plantlet,  developed  in  an  ovule  through 
fertilization  by  pollen.  Their  spores  (97),  or  the  bodies  produced  in 
their  fructification  by  which  they  are  jn-opagated,  and  which  there- 
fore answer  to  seeds,  are  single  cells,  at  least  in  most  cases.  These, 
as  they  germinate  in  the  soil,  or  whatever  medium  they  live  in,  un- 
dergo a  development  at  the  time  of  their  germination  which  has  been 
compared  with  that  of  the  embryonal  vesicle  (579)  during  its  devel- 
opment into  the  embryo  in  the  ovule  ;  and  by  growth  directly  give 
rise  to  the  plant. 

653.  It  was  once  thought  probable,  that  these  spores  were  pro- 
duced, and  were  capable  of  developing  into  the  plant  without  being 
fertilized  by  other  cells  answering  to  pollen  ;  or  at  least  that  this  was 
the  case  in  all  the  lower  orders,  such  as  Algas  and  Fungi,  and  in  some 
of  the  highest,  such  as  Ferns.  But  the  sagacious  Linna?us,  by  nam- 
ing them  Cryptogamous  plants  (i.  e.  plants  with  concealed  organs  of 
reproduction)  seems  to  have  recorded  his  belief  that  they  were  really 
bisexual,  or  furnished  with  two  sorts  of  organs,  the  fertilizing  and  the 
fertilized.  A  series  of  important  discoveries,  for  the  most  part  of 
recent  date,  have  proved  this  to  be  so,  —  have  made  known  a  true 
fecundation  in  numerous  species  of  every  Cryptogamous  order,  and 
in  their  lowest  as  well  as  their  highest  forms,  thus  leaving  no  doubt 
of  its  universality.  The  apparatus  and  the  processes  of  reproduction, 
however,  are  wonderfully  varied  in  the  different  groups  of  Cryp- 


332 


REPRODUCTION    IN 


togamous  plants.  A  few  examples  may  be  adduced,  illustrative  of 
the  principal  modes,  beginning  with  the  simplest  plants. 

654.  Reproduction  in  Plants  of  a  Single  Cell  (100).    All  such  simple 

one-celled  plants  as  Protococcus  and  the  like  (Fig.  79  -  83,  18  -  22), 
Desmidiaceas  and  Diatomaceae,  are  freely  propagated  by  cell-multi- 
plication (33  -  3G),  —  the  division  of  their  protoplasm  or  whole  living 
mass  into  bodies  which  directly  become  new  cells  like  the  parent, — 
or  by  original  cell-formation  in  their  interior  (29).  This  is  non- 
sexual reproduction,  and  essentially  answers  to  the  well-known  prop- 
agation of  Phoenogamous  plants  by  buds,  bulbs,  offsets,  &c.  It  is 
probable  that  this  may  not  go  on  indefinitely  in  any  plant.  At  any 
rate,  not  only  do  all  the  higher  plants  propagate  in  a  different  way, 
viz.  by  flowers,  producing  seeds,  but  probably  all  plants  of  the  lower 
grade  also  have  a  sexual  reproduction  in  some  form  or  other.  It  is 
certainly  the  case  in  many  one-celled  plants,  and  in  others  almost 
equally  simple  in  structure.  As  in  Phamogainous  plants,  sexual 
reproduction  essentially  depends  upon  the  mingling  of  the  materials 
of  two  distinct  cells  (as  the  pollen-cell  and  the  embryonal  vesicle, 
579)  ;  and  these  cells  in  the  lowest  forms  of  vegetation  represent 
individual  plants.  The  simplest  mode  of  such  reproduction  in  the 
lowest  plants,  and  that  longest  known,  is  what  has  been  termed 

655.  Conjugation.     This  is  the  mode  in  which  two  vast  tribes  of 
microscopic  one-celled  aquatic  plants,  the  Desmidiaceaa  and  Diato- 

maceoe,  are  reproduced.  They  multi- 
ply rapidly,  and  apparently  without 
Jimit,  by  successive  division  into  two 
equal  parts,  which  separate,  each  be- 
coming like  the  original.  But  at  length 
two  of  these  individuals,  being  en- 
dowed with  the  power  of  movement, 
come  into  contact ;  the  firm  or  often 
silicious  cell-wall  ruptures  or  gives 
way  in  a  definite  manner  at  the  place 
of  junction,  and  the  whole  contents  of 
the  two  conjugating  cells  or  individu- 
als are  commingled  into  one  mass  of 
protoplasm,  &c. ;  this  soon  has  a  coat  of  cellulose  formed  around  it, 


FIG.  631.  Magnified  individual  of  Closterium  aeutum,  after  Ilalfs.  632.  Two  individuals 
more  magnified,  in  conjugation  ;  their  cells  opening  one  into  the  other,  and  the  contents  min- 
gled ;  in  633,  condensing  ;  in  634,  collected  and  formed  into  a  spore. 


CRYPTOGAMOUS    OR    FLOWERLESS    PLANTS. 


333 


and  is  new  a  spore,  which  when  it  grows  begins  a  new  series  of  in- 
dividuals developed  by  successive  division. 

656.  In  Algae  consisting  of  a  Single  Row  of  Cells  one  tribe  presents 

the  same  mode  of  reproduction,  and  the  various  species  of  Zygnema 
or  Spirogyra,  found  in  almost  every  pool  of  fresh 
water  at  different  times  in  spring  and  summer, 
afford  the  readiest  illustrations  of  conjugation, 
which  low  powers  of  the  microscope  suffice  to 
exhibit.  These  green  threads  when  magnified 
are  seen  to  consist  of  single  rows  of  cylindrical 
cells  joined  end  to  end.  The  cells  being  all 
alike  and  equally  capable  of  conjugation,  each  is 
as  it  were  an  individual.  At  a  certain  season, 
a  protuberance  appears  on  the  corresponding 
parts  of  certain  cells  of  two  adjacent  threads ; 
the  budding  growth  continues  until  the  two 
come  into  contact ;  the  intervening  walls  are 
then  absorbed,  opening  a  free  communication 
between  the  cavities  of  the  two  cells  ;  mean- 
while the  green  matter  and  protoplasm,  before 
arranged  in  some  definite  shape  in  each  species 
(more  commonly  in  one  or  more  spiral  bands), 
break  up  into  a  granular  mass  floating  in  the 
water  of  the  cell ;  this  all  passes  over  from  one 
cell  to  the  other,  —  sometimes  to  the  one  plant  and  sometimes  to  the 
other  in  adjacent  cells,  —  and  is  mingled  with  the  similar  contents  of 
the  cell  which  receives  it ;  and  the  united  product  is  condensed  into 
a  green  protoplasmic  mass,  which,  acquiring  a  coat  of  cellulose,  be- 
comes a  new  cell  or  spore,  in  due  time  germinating  into  a  iicav  plant. 

657.  In  reproduction  by  conjugation,  the  two  cells  or  individuals 
concerned  are  alike ;  one  is  as  much  the  fertilizer  or  the  fertilized 
as  the  other.  But  the  clear  distinction  of  sexes  which  all  the  higher 
Cryptogamous  no  less  than  Phasnogamous  plants  exhibit,  is  also  mani- 
fested in  those  of  the  simplest  structure,  viz.  in  plants  consisting  of 
single  cells,  or  of  rows  or  clusters  of  similar  and  essentially  inde- 
pendent cells.     That  is,  even  these  afford  examples  of 

FIO.  635.  Magnified  view  of  two  conjugating  filaments  of  Zygnema,  showing  all  the  stages 
of  the  process  by  which  the  cells  from  two  filaments  form  each  a  corresponding  protuberance, 
these  come  into  contact,  the  intervening  walls  are  absorbed,  and  the  contents  pass  from  one 
cell  into  the  other,  condense,  acquire  an  investing  membrane,  and  so  form  a  spore  :  the  stages 
are  represented  from  above  downwards  ;  a  completed  spore  is  seen  at  the  bottom,  on  the  right. 


334  REPRODUCTION   IN 

658.  Direct  Fertilization  of  Spores  by  Spermatozoids  from  an  Anthc- 

l'idium ;  the  latter  answering  to  the  anther,  or  essential  part  of  the 
stamen,  of  Phsenogamous  plants.  Colin  *  has  shown  that  even 
Volvox  —  an  undoubted  vegetable,  consisting  of  microscopic  one- 
celled  plants  of  rounded  form,  grouped  into  a  spherical  colony  —  has 
a  true  sexual  propagation,  like  that  of  the  higher  green  Alga?,  some 
of  the  individuals  or  cells  of  the  sphere  producing  antheridia  or  fer- 
tilizing cells,  while  others  produce  spores,  or  bodies  which  become 
such  on  being  fertilized  by  the  antheridia,  which  alone  renders  them 
capable  of  germination.  A  good  general  idea  of  bisexual  reproduction 
in  the  simplest  Algaj  may  best  be  obtained  from  a  brief  abstract  of 
Avhat  has  lately  been  discovered  by  Pringsheim  and  Cohn  in  two  or 
three  common  species  of  comparatively  easy  investigation. 

659.  Vaucheria  is  a  genus  of  several  species  of  green  Alga?,  con- 
sisting of  simple  but  indefinitely  branching  cells  (Fig.  89).  In  fruc- 
tification, the  whole  contents  of  the  more  or  less  enlarged  extremity 
of  some  of  the  branches,  or  of  a  special  projection  from  the  side 
of  the  cell,  separate  from  the  general  contents  of  the  plant,  con- 
dense into  a  globular  green  mass  (Fig.  89  a),  and  become  a  spore, 
which  at  length  escapes  by  a  rupture  of  the  walls  (Fig.  90),  moves 
freely  about  in  the  water  for  some  hours,  then  fixes  itself,  and  ger- 
minates, elongating  directly  into  a  thread-like  and  at  length  branch- 
ing plant,  like  the  parent.  Here  there  appears,  and  was  generally 
thought  to  be,  reproduction  without  fecundation.  Vaucher,  however, 
more  than  half  a  century  ago,  noticed  one  or  more  horn-shaped  pro- 
jections in  the  vicinity  of  the  spore-bearing  portion,  which  he  sus- 
pected to  be  the  analogues  of  the  anther.  Nothing  had  been  found 
to  verify  this  view  until  the  year  1854,  when  Pringsheim,  of  Berlin, 
discovered  the  fecundation  and  verified  this  conjecture.  The  horn- 
shaped  body  is  an  antheridium,  or  the  analogue  of  the  anther.  It 
produces  myriads  of  extremely  minute  corpuscles,  of  oblong  shape, 
and  furnished  with  a  bristle  or  cilia  at  each  end,  by  the  vibration  of 
which  they  move  freely  in  the  water.  These  are  spermatozoids  (so 
called  from  their  obvious  resemblance  to  the  spermatozoa  of  ani- 
mals), and  the  analogues  of  pollen.  At  the  proper  time  the  anthe- 
ridium bursts  at  the  summit,  and  discharges  the  spermatozoids  ;  at 
this  time  the  wall  of  the  projection  which  contains  the  spore  likewise 
opens ;  numbers   of  the   free-moving  spermatozoids  find  their  way 

*  In  Comples  Rendus,  vol.  43,  185G,  and  Ann.  Set.  Nat.  scr.  4,  vol.  5,  p.  323. 


CRYPTOGAIMOUS   OR   FLOWERLESS   PLANTS.  33a 

into  the  opening  and  into  contact  with  the  forming  spore,  or  even 
penetrate  its  substance ;  it  being  an  amorphous  mass,  coated  with 
protoplasm  only.  But,  as  a  consequence  of  fecundation  by  one  or 
more  spermatozoids,  a  wall  of  cellulose  is  presently  formed  on  its 
surface,  converting  it  into  a  proper  specialized  cell  or  spore.* 

660.  JEdogonium  is  a  genus  of  simple  Alga?  of  the  Conferva  tribe, 
consisting  of  a  row  of  cylindrical  cells  placed  end  to  end,  as  in  Fig. 
639.  Some  of  these  cells,  usually  shorter  than  the  rest,  become 
tumid,  and,  without  conjugation,  have  their  whole  green  contents 
transformed  into  a  spore  resembling  that  of  Zygnema  (Fig.  635) 
and  Vaucheria  (Fig.  90).  The  fertilization  of  this  spore  has  re- 
cently been  discovered  by  Pringsheim.f  He  ascertained  that  other 
cells  of  the  same  little  plant  produce  a  great  number  of  minute 
ovoid  bodies,  which  he  names  Androspores :  these  escape  by  the 
opening  of  the  mother  cell,  moving  about  freely  by  the  vibration  of  a 
crown  of  cilia  attached  near  the  smaller  end.  One  or  more  of  these 
androspores  fix  themselves  by  the  smaller  end  upon  the  surface  of 
the  cell  in  which  a  large  ordinary  spore  is  forming,  or  in  the  vicinity, 
and  germinate  there,  growing  longer  and  narrower  at  the  point  of 
attachment,  while  near  the  free  end  a  cross  partition  forms,  and  some- 
times another,  making  one  or  two  small  cells  ;  this  is  the  true  anthe- 
ridium ;  for  in  it  a  crowd  of  spermatozoids  are  formed,  also  endowed 
with  motivity  by  means  of  vibratile  cilia.  Now  the  top  of  the  an- 
theridium  falls  off  as  a  lid,  the  spermatozoids  escape ;  the  spore-cell 
at  this  time  opens  at  the  top ;  one  of  the  spermatozoids  enters  the 
opening,  its  pointed  end  foremost ;  this  becomes  stationary  upon  or 
slightly  penetrates  the  surface  of  the  young  spore,  into  which  its 
contents  are  probably  transferred,  by  rupture  or  by  endosmosis,  and 
a  coat  of  cellulose  is  then,  but  not  till  then,  deposited  upon  it,  com- 
pleting its  organization  as  a  spore.  This  spore,  as  in  the  preceding 
cases,  in  due  time  germinates,  and  grows  directly  into  a  plant  like 
the  parent.  But  in  Bolbochsete,  according  to  Pringsheim,  and  in 
Sphreroplea,  as  investigated  by  Cohn,j  the  spore  in  germination 
converts  its  contents  by  successive  division  into  a  large  number  of 
small,  oval  or  oblong  bodies,  furnished  with  two  long  cilia  on  a  short 


*  Pringsheim,  in  the  Proceedings  of  the  Royal  Academy  of  Sciences,  Berlin, 
March,  1855,  and  Ann.  Sci.  Nat.  ser.  4,  vol.  3,  p.  363. 

t  Op.  supra  cit.  May,  1856,  and  Ann.  Sci.  Nat.  ser.  4,  vol.  5,  p.  250. 
t  Op.  supra  cit.  May,  1855,  and  Ann.  Sci.  Nat.  1.  c.  p.  186,  pi.  12,  13. 


336  REPRODUCTION   IN 

beak  at  one  end,  and  which  from  their  extreme  resemblance  to  ani- 
malcules and  their  lively  movements  are  called  Zoospores.  And 
these  zoospores  germinate  by  elongation  and  the  formation  of  trans- 
verse partitions  into  adult  thread-like  plants,  consisting  of  a  row  of 
cells.  The  whole  contents  of  the  cells  of  some  adult  individuals  of 
Sphaeroplea  are  formed  into  large  green  spores,  as  yet  without  a  coat ; 
those  of  different  individuals  give  rise  to  myriads  of  slender  sperma- 
tozoids,  moving  by  means  of  a  pair  of  cilia  fixed  at  the  narrow  end. 
These  escape  from  the  parent  cell  through  a  small  perforation  which 
now  appears,  enter  the  spore-bearing  cells  of  the  fertile  plant 
through  a  similar  perforation,  play  around  the  spores,  and  at  length 
one  or  more  of  them  drives  its  pointed  extremity  into  their  naked 
surface ;  after  which,  fertilization  being  accomplished,  a  thick  coat 
of  cellulose  is  deposited  to  complete  the  spore. 

6G1.  That  in  the  Fucaceoe  or  olive-green  SeaAveeds,  the  highest 
tribe  of  Algo?,  the  large  spores  are  fecundated  by  spermatozoids,  or 
minute  lively-moving  cells  produced  in  antheridia,  was  demonstrated 
by  Thuret  in  the  year  1850.*  And  in  more  recent  memoirs  |  he 
has  shown  that  the  fertilization  takes  place  through  direct  contact  of 
the  spermatozoids  with  the  naked  surface  of  the  unimpregnated  spore, 
then  having  only  a  protoplasmic  coating ;  and  that  these  spores  will 
not  develop  unless  so  fertilized.  Through  the  researches  of  Thuret 
and  others,  antheridia  are  now  well  known  in  the  remaining  or 
rose-red  series  of  Algoe,  although  their  spermatozoids  are  not  known 
to  be  endowed  with  motivity.  The  same  appears  to  be  the  case  with 
Lichens,  the  bodies  described  by  Itsigsohn,j  being  probably  of  the 
nature  of  spermatozoids  or  fertilizing  cells.  In  the  vast  family  of 
Fungi  there  arc  similar  indications  of  antheridia  and  spermatozoids, 
but  the  fecundation  is  not  yet  clearly  made  out. 

GG2.  Fertilization  by  Spermatozoids  of  a  Cell  in  a  Pislilidium,  which 

becomes  a  Sporangium.  In  all  the  foregoing  cases,  the  spores  them- 
selves are  the  subjects  of  direct  fertilization.  But  in  Mosses, 
Liverworts,  &c.  (in  which  the  two  kinds  of  organs  have  long  been 
recognized  and  their  functions  to  some  extent  understood),  the 
contents   of  the   antheridium  act  upon   an  organ  which,  in  conse- 


*  Ann.  Sci.  Nat.  scr.  3,  vol.  14  and  16,  1850-1.      See  Harvey,  Nereis  Bor. 
Amer.  in  Smithsonian  Contributions,  1852,  &c. 
t  Op.  cit.  ser.  4,  vol.  2  and  3,  1854,  1855. 
J  In  Botanische  Zeilung,  1850. 


CRYPTOGAMOUS    OR   FLOWERLESS   PLANTS.  337 

quence  of  fertilization,  develops  into  a  sort  of  pod,  the  Sporangium 
or  Spore-case,  filled  with  a  multitude  of  spores  which  receive  no  in- 
dividual fecundation ;  this  organ,  from  its  general  analogy  to  the 
pistil,  has  been  termed  a  Pistillidium.     The  antheridia  of  Mosses 
and  the  like  occur  either  in  the  axils  of  the  leaves,  or  collected 
into  a  head  at  the  summit   of  the  stem.     They   are   found  either 
in  the  same  heads  as  the  pistillidia,  or  in  distinct  heads    on   the 
same   individuals    (monoecious),  or   on    separate   individuals   (dioe- 
cious).     The    antheridium    (Fig.    1307)    is    merely   a    cylindrical 
or  club-shaped  sac,   composed   of  a  single    layer    of  cells,   united 
to  form  a  delicate  membrane ;    within    which  are    developed  vast 
numbers  of  minute,  very  delicate  cells,  completely  filling  the  sac. 
The  sac  bursting  at  its   apex  when  mature,  the  delicate  vesicles 
are  discharged.     Each  of  these  contains  a  slender  filament,  thick- 
ened at  one  end  and  tapering  off  to  a  fine  point  at  the  other :  it  may 
be  seen  through  the  transparent  walls,  spirally  coiled  up  in  the  interior 
of  each  vesicle.     When  these  vesicles  are  extruded  in  water  under 
the  microscope,  the  contained  filaments  may  be  seen  to  execute  lively 
movements,  wheeling  round  and  round  in  the  vesicle,  or,  when  dis- 
engaged from  the  latter,  and  assuming  a  corkscrew  form,  at  the  same 
time  advancing  forward,  the  thin  end  of  the  filament  almost  always 
preceding.      Minute  observation,  which  is  very  difficult,  both  from 
the  rapidity  of  the  motion  (which,  however,  is  arrested  by  poisons) 
and  from  the  great  delicacy  of  the  whole  structure,  shows  that  the 
movements  arise  from  two  long  and  extremely  delicate  cilia,  attached 
to  the  tapering  end  of  the  filament.     These  are  the  spermatozoids, 
or  true  fertilizing  organs.     The  pistillidia  (Fig.  1306),  which  ap- 
pear at  the  same  time  as  the  antheridia,  and  often  mixed  with  them, 
are  flask-shaped  bodies  (like  an  ovary  in  shape),  with  a  long  neck 
(resembling  a  style),  composed  of  a  cellular  membrane.     The  neck 
is  perforated  by  an  open  canal,  leading  to  a  cavity  below,  at  the  base 
of  which  a  single  cell  is  the  germ  of  the  future  sporangium  or  spore- 
case.     Upon  this  the  spermatozoids,  or  spiral  filaments  of  the  an- 
theridia, act,  one  or  more  of  them  reaching  it  by  finding  their  way 
down  the  canal  of  the  pistillidium.     Then  this  cell  commences  a 
special  development,  divides  into  two,  and  proceeds  by  ordinary  cell- 
multiplication  to  build  up  the  sporangium  or  capsule,  in  which  a 
countless  number  of  minute  spores  are  produced.     The  spores   of 
Mosses  are  formed  in  the  same  way  as  pollen-grains,  which  they 
much  resemble  in  structure,  being  single  cells  with  a  double  coat,  of 
29 


338  REPRODUCTION    IN 

which  the  inner  is  the  true  cell-wall,  and  the  outer  a  sort  of  secre- 
tion from  it.  In  germination,  the  inner  or  proper  membrane  of  the 
spore  swells,  and  protrudes,  from  any  part  of  its  surface  favorably 
situated,  a  tubular  process,  which  forms  partitions  as  it  elongates 
and  branches,  giving  rise  to  what  has  been  fancifully  named  a  pro- 
embryo,  or,  better,  a  prothallus,  —  a  rudimentary  plantlet  very  unlike 
a  Moss,  but  closely  resembling  a  branched  Conferva,  consisting,  as 
it  does,  merely  of  ramified  threads,  or  rows  of  cells.  After  a  time 
certain  cells  of  its  A'arious  branches,  taking  a  special  development, 
produce  buds,  which  are  soon  covered  with  a  tuft  of  rudimentary 
leaves,  and  grow  up  into  the  leafy  stems  of  the  perfected  plant.  Here 
a  single  spore  —  or  rather  a  peculiar  transitory  plantlet  developed 
from  it  —  gives  rise  at  once  to  a  number  of  individuals.  And  in 
fecundation  it  is  not  the  spores  themselves  that  are  fertilized,  but 
a  cell  which  by  its  development  gives  origin  to  a  sj)ore-case,  and  this 
to  a  vast  number  of  spores* 

6G3.  Fertilization  of  a  Cell  of  a  Prothallus,  or  peculiar  germinating 
Plantlet,  which  thereupon  develops  into  a  Plant.  Tins  most  extraordi- 
nary mode  of  fecundation  has  recently  been  discovered  in  the  Ferns 
and  other  of  the  higher  Cryptogamous  orders.  The  fructification  of 
F'erns  consists  of  spore-cases  alone,  which  are  borne  on  the  back, 
margins,  or  some  other  part  of  their  leaves  (Fig.  1287-1294),  and 
are  filled  with  spores  resembling  those  of  Mosses.  Since  Mosses  have 
long  been  known  to  have  organs  answering  in  function  to  stamens, 
as  well  as  those  answering  to  pistils,  and  since  Ferns  are  regarded 
as  plants  of  higher  rank  than  Mosses,  their  antheridia  were  diligent- 
ly sought  for  upon  the  fructifying  plants,  but  in  vain  ;  and  botanists 
were  therefore  forced  to  the  unwilling  conclusion,  that  the  highest 
organized  of  Cryptogamous  plants  were  asexual.  But  antheridia, 
essentially  like  those  of  Mosses,  have  been  at  length  detected,  not  upon 
the  mature  and  fructifying  plant,  but  upon  the  germinating  plantlet. 
The  germination  of  the  spores  of  Ferns  had  long  since  been  ob- 
served. The  process  begins  in  the  same  manner  as  in  Mosses  ;  but 
the  extremity  of  the  tubular  prolongation  of  the  spore,  converted 
by  partitions  into  a  row  of  cells,  is  developed  into  an  expanded,  leaf- 
like body  (the  pro-embryo,  or  prothallus  as  it  is  now  called),  which 

*  The  fullest  account  is  by  Hofmeister,  Vergleichende  Untersuchungcn  der 
Keimung,  Entfaltung,  und  Fruchtbildung  Hoherer  Kryptogamen,  etc. — Leipsic, 
1851. 


CRYFTOGAMOUS    OR    FLOWERLESS    PLANTS.  339 

on  a  small  scale  resembles  a  frondose  liverwort.  Upon  this  body, 
Niigeli,  in  1844,  found  moving  spiral  filaments,  like  tbose  of  the  an- 
theridia  of  Mosses,  &c.  This,  as  Henfrey  remarks,  "  seemed  to 
destroy  all  grounds  for  the  assumption  of  distinct  sexes,  not  only  in 
the  Ferns,  but  in  the  other  Crypt ogamia ;  for  it  Avas  argued  that  the 
existence  of  these  cellular  organs  producing  moving  spiral  filaments 
(the  so-called  spermatozoa)  upon  the  germinating  fronds,  proved  that 
they  were  not  to  be  regarded  as  in  any  way  connected  with  the 
reproductive  processes.  But  an  essay  published  by  the  Count 
Suminski  in  1848  totally  changed  the  face  of  the  question."  On 
the  under  side  of  the  delicate,  Marchantia-like,  germinating  frond, 
Suminski  found  a  number  of  cellular  organs  of  two  distinct  kinds, 
answering  to  antheridia  and  pistillidia.  The  former,  which  are  the 
more  numerous,  are  cells  elevated  on  the  surface  of  the  germinating 
frond,  in  the  cavity  of  which  are  formed  other  cells,  filled  with 
minute  vesicles  containing  each  a  spiral  filament  coiled  up  in  its  in- 
terior. The  organ  bursts  at  its  summit,  and  discharges  the  vesicles 
in  a  mucilaginous  mass  ;  the  spiral  filaments  moving  within  the 
vesicles  at  length  make  their  way  out  of  them  and  swim  about  in 
the  water.  These  filaments,  or  spermatozoids,  resemble  those  of 
Mosses,  but  are  flat  and  ribbon-like,  as  in  Chara,  and  possess  accord- 
ing to  Suminski  about  six,  according  to  Thuret  numerous  cilia,  by 
whose  vibrations  they  are  moved.  The  pistillidia,  if  they  may  be 
so  called,  are  rounded  cavities  in  the  cellular  tissue  of  the  same  body, 
opening  on  the  under  side,  in  the  bottom  of  which  is  a  single  glob- 
ular cell,  from  which  the  future  growth  proceeds.  One  or  more  of 
the  active  spermatic  filaments,  liberated  by  the  bursting  of  the  an- 
theridia, have  been  found  to  enter  the  open  pistillidium,  and  to  come 
to  rest  and  then  wither  away  in  contact  with  this  specialized  cell. 
The  latter  now  develops  into  a  bud,  or  embryo,  as  it  may  perhaps 
be  termed,  winch  grows  in  the  ordinary  way,  producing  an  abbrevi- 
ated axis,  sending  roots  downward  and  leaf  after  leaf  upwards  ;  and 
so  producing  the  mature  Fern.*  And,  as  most  Ferns  are  perennial 
plants,  they  produce  year  after  year  their  fructification  (consisting 

*  The  English  reader  is  referred  to  Hcnfrey's  Translation  of  Mohl's  Anatomy 
and  Pliysiolor/y  of  the  Vegetable  Cell ;  and  Henfrey's  Report  on  the  Reproduction 
and  supposed  Existence  of  Sexual  Organs  in  the  higher  Crijptogamous  Plants,  in  the 
Report  of  the  BritislT  Association  for  the  Advancement  of  Science,  for  1851, 
reprinted  in  Silliman's  Journal,  Vol.  14  and  15  ;  from  which  the  above  account 
has  been  condensed. 


340  SPECIAL    DIRECTIONS    AND 

merely  of  spores  in  spore-cases),  without  any  known  limit,  and  with- 
out any  other  fecundation  than  that  which  occurred  at  first  upon  the 
germinating  plantlet. 

664.  In  Ferns,  accordingly,  it  is  not  the  sporangium  that  is  fer- 
tilized, still  less  the  spores,  but  a  cell  of  a  peculiar  transitory  plant- 
let  formed  by  the  germination  of  a  spore.  This  cell  otherwise  will  not 
develop  at  all ;  but  when  thus  fecundated,  it  develops  like  a  bud,  and 
grows  into  a  plant  of  indefinite  longevity,  capable  of  fructifying  by  a 
true  parthenogenesis  (571)  throughout  its  long  existence.  This  is 
also  known  to  be  the  case  with  Equisetaceaa ;  and  the  Lycopodia- 
ceae  or  Club-Mosses  and  other  vascular  Cryptogamous  Plants  are 
thought  to  have  analogous  fecundation,  although  the  details  as  yet 
are  not  well  made  out. 


CHAPTER     XIII. 

OF   THE   SPONTANEOUS   MOVEJMENTS   AND   VITALITY   OF   PLANTS. 

665.  The  facts  brought  to  view  in  the  preceding  chapter,  namely, 
that  either  the  spores  or  the  fertilizing  corpuscles  or  filaments  of 
most  Cryptogamous  plants  of  every  order  are  temporarily  endowed 
with  motivity,  naturally  raises  the  inquiry  whether  such  phenomena 
are  altogether  exceptional  in  the  vegetable  kingdom,  or  whether  the 
power  of  executing  movements  is  not  a  general  endowment  of  plants 
as  well  as  of  animals,  although  in  lesser  degree.  As  we  pass  in  re- 
view the  various  phenomena  exhibited  Jby  plants  in  this  respect,  and 
at  the  same  time  consider  that  self-caused  motion,  internal  or  exter- 
nal, or  the  faculty  of  directing  motion,  is  a  necessary  concomitant  of 
life,  we  shall  probably  arrive  at  the  conclusion,  that  this  surprising 
activity  of  the  microscopic  spores  and  spennatozoids  of  Cryptogamous 
plants  is  not  altogether  anomalous,  —  that  these  are  merely  more 
vivid  manifestations  of  a  power  which  they  share  with  ordinary  vege- 
tables, —  that  plants  are  endowed  with  life  no  less  really  than  ani- 
mals, —  that  the  distinction  between  plants  and  the  lower  animals  in 
this  respect  is  one  of  degree  rather  than  of  kind,  —  and  that  it  is  a 
characteristic  of  living  things  to  move. 


SPONTANEOUS    MOVEMENTS   IN   PLANTS.  341 

666.  The  Special  Directions  which  the  parts  of  all  plants  assume  are 
the  result  of  self-caused  movements,  although  such  movements  are 
mostly  much  too  slow  to  be  directly  observed.  Among  these  the 
most  universal  are  the  descent  of  the  root  in  germination,  the  ascent 
of  the  stem  into  the  light  and  air,  and  the  turning  of  branches  and 
the  upper  surface  of  leaves  towards  the  light  (120,  131,  294). 
These  directions  evidently  are  not  the  result  of  mere  growth.  It  is 
not  that  the  root  grows  downwards  and  the  stem  upwards  ;  but  the 
root  end  of  the  elongating  radicle  bends  or  curves  in  the  course  of 
its  growth  so  as  to  point  downwards  if  not  already  in  that  position, 
and  the  other  extremity,  with  the  plumule,  curves  upwards,  and  the 
young  stem,  after  reaching  the  light,  if  unequally  illuminated,  bends 
towards  the  stronger  light. 

667.  Strenuous  attempts  have  been  made  to  explain  these  changes 
of  direction  upon  mechanical  principles.  Mr.  Knight  thought  that 
the  descent  of  the  root  and  the  ascent  of  the  stem  were  caused  by 
gravitation ;  and  he  seemed  to  show  tliis  by  his  celebrated  experi- 
ments of  removing  germinating  seeds  from  the  influence  of  gravita- 
tion, and  causing  the  root  and  stem  to  take  a  different  direction  in 
obedience  to  a  different  force.  He  fixed  some  beans  ready  to  ger- 
minate in  a  quantity  of  moss  upon  the  circumference  of  a  wheel,  and 
made  it  to  revolve  vertically  at  a  rapid  rate  ;  replacing  the  effect  of 
gravity  by  centrifugal  force.  On  examination,  after  some  days,  the 
young  root  was  found  to  have  turned  towards  the  circumference,  and 
the  stem  towards  the  centre  of  the  wheel.  The  same  result  took 
place  when  the  wheel  was  made  to  revolve  horizontally  with  con- 
siderable rapidity ;  but  when  the  velocity  was  moderate,  the  roots 
were  directed  obliquely  downwards  and  outwards,  and  the  stems 
obliquely  upwards  and  inwards,  in  obedience  both  to  the  centrifugal 
force  and  the  power  of  gravitation,  acting  at  right  angles  to  each 
other.  It  remained  for  Mr.  Knight  to  explain  how  the  same  force, 
gravitation,  could  produce  such  opposite  effects,  causing  the  stem  to 
ascend  as  well  as  the  root  to  descend.  This  he  ingeniously  at- 
tributed to  their  different  mode  of  growth.  The  root  growing  at  its 
extremity  only,  he  supposed  that  the  soft  substance  of  the  growing 
point  would  be  acted  upon  by  gravity  like  an  imperfect  solid,  and 
accumulated  on  the  lower  side ;  while  the  stem,  growing  by  the 
elongation  of  an  internode  or  a  series  of  internodes  already  formed,  its 
solid  tissues  would  be  unaffected  by  gravity,  which  could  affect  only 
its  nutritive  juices,  causing  their  accumulation  on  the  lower  side  of  a 

29* 


342  SPECIAL    DIRECTIONS    AND 

stem  out  of  the  perpendicular  line ;  which  side,  thus  more  actively 
nourished,  would  grow  more  vigorously  than  the  upper,  and  so  cause 
the  stem  to  turn  upwards.  To  show  how  baseless  this  ingenious 
hypothesis  is,  we  have  only  to  remember,  on  the  one  hand,  that  the 
fluid  contents  of  the  cells  of  plants  arrange  themselves  in  obedience 
to  other  forces  than  gravity,  and  freely  rise  against  its  influence  to 
the  summit  of  the  loftiest  trees,  so  that  gravity  could  establish  no 
difference  within  the  diameter  of  a  germinating  stem  ;  and  on  the 
other,  that  the  root  in  germination,  if  fixed  upon  its  surface,  will  pen- 
etrate a  fluid  of  greater  weight  than  itself,  such  as  mercury.  More- 
over, Schultz  and  Mohl  have  shown  that,  by  careful  management  in 
reversing  the  ordinary  conditions,  —  as  by  germinating  seeds  in 
damp  moss,  so  arranged  that  the  only  light  they  could  receive  was 
reflected  from  a  mirror,  which  threw  the  solar  rays  upon  them  directly 
from  below,  —  the  ordinary  direction  of  the  organs  could  be  reversed, 
the  roots  turning  upwards  into  the  dark  and  damp  moss,  and  the 
stems  downAvard  into  the  light.  This  would  prove  that  light  has 
more  effect  than  gravitation,  or  any  other  imaginable  influence  of  the 
mass  of  the  earth.  Yet, —  what  shows  that  there  is  some  real  relation 
between  the  direction  assumed  by  the  plant  and  the  earth,  —  stems 
which  grow  in  complete  darkness  always  point  to  the  zenith,  as  is 
seen  in  the  shoots  of  vegetables  in  perfectly  dark  cellars,  and  in  the 
elongated,  constantly  upright  stemlet  of  germinating  seeds  too  deeply 
buried  to  receive  any  light  before  they  reach  the  surface  of  the  soil. 

668.  The  influence  of  a  mass  in  some  way  analogous  to  attrac- 
tion is  also  observed  in  the  germination  of  the  Mistletoe.  Its  form- 
ing root  turns  regularly  to  the  trunk  or  branch  upon  which  it  is 
parasitic,  just  as  those  of  ordinary  plants  turn  to  the  earth.  And 
that  it  is  the  mass  and  not  the  quality  of  the  body  which  determines 
the  direction,  is  seen  when  germinating  seeds  of  the  Mistletoe  are 
fixed  close  to  the  surface  of  a  cannon-ball :  all  the  roots  as  they 
grow  point  to  its  centre  and  advance  to  its  surface,  just  as  they  do 
to  the  branch  of  a  tree  which  they  penetrate. 

669.  When  the  stem  has  emerged  from  the  earth  into  the  light  of 
day,  this  exerts  a  controlling  influence  over  its  direction.  Young 
and  green  stems  always  tend  to  expose  themselves  as  much  as  possi- 
ble to  the  light,  and  bend,  very  promptly  when  delicate,  towards  the 
most  illuminated  side,  as  is  well  observed  when  plants  are  raised  in 
an  apartment  lighted  from  a  single  aperture :  and  consequently  in 
the  open  air,  being  equally  illuminated  on  all  sides,  they  grow  up- 


SPONTANEOUS    MOVEMENTS    IN   PLANTS.  343 

right.  De  Candolle  attempted  a  mechanical  explanation  of  this 
bending  of  green  stems  towards  the  light,  connecting  it  with  assimi- 
lation and  growth.  He  supposed  that,  as  the  side  upon  which  the 
light  strikes  will  fix  most  carbon  by  the  decomposition  of  carbonic 
acid  (34G  -  348),  so  its  tissue  will  solidify  faster,  and  therefore  elon- 
gate less,  than  the  shaded  side  (which  will  become  drawn,  as  the 
gardener  terms  it)  ;  and  the  stem  or  branch  will  necessarily  bend 
towards  the  shorter  or  illuminated  side.  But  when  the  light  is 
equally  diffused  around  a  plant,  the  decomposition  of  carbonic  acid 
will  take  place  uniformly  on  all  sides,  and  the  perpendicular  direc- 
tion naturally  be  maintained.  Two  facts  at  once  demolish  this  in- 
genious theory.  1.  It  is  now  well  known  that,  under  the  solar 
spectrum,  the  decomposition  of  carbonic  acid  in  the  green  parts  of 
plants  is  effected  chiefly  by  the  most  luminous  rays,  that  is,  by  yellow 
light,  and  next  to  this  by  orange  and  red ;  whereas  the  bending  is 
strongest  under  the  violet  and  blue  rays,  the  yellow  producing  little 
curvature,  and  the  red  none  at  all.  2.  When  a  stem  curved  under 
the  light  is  split  from  the  apex  downwards,  so  as  to  separate  the 
illuminated  from  the  shaded  side,  the  former  curves  more  than  be- 
fore, while  the  latter  tends  to  straighten,  —  showing  that  it  was 
pulled  over  by  the  contraction  of  the  concave  side,  and  not  pushed 
over  by  its  own  greater  growth.  From  all  this  it  clearly  appears 
that  the  turning  of  parts  towards  the  light,  and  the  other  special 
directions  of  plants,  are  independent  of  growth,  and  apparently  are 
effected  by  some  inherent  power.  At  least,  they  have  thus  far 
proved  no  more  susceptible  of  mechanical  explanation  than  the  more 
marked  movements  of  animals. 

670.  In  leaves  it  is  the  denser  and  deeper  green  upper  surface 
(262)  that  is  presented  to  the  light,  while  the  paler  lower  surface,  of 
looser  tissue,  avoids  it.  The  recovery  of  the  natural  position,  when 
the  leaf  is  artificially  reversed,  is  the  more  promptly  effected  in  pro- 
portion to  the  difference  in  structure  and  hue  between  the  two  strata. 
This  movement  is  so  prompt  in  some  plants,  that  their  leaves  follow 
the  daily  course  of  the  sun.  The  leaf  is  more  capable  of  executing 
such  movements,  on  account  of  its  extended  surface,  and  its  pliancy, 
and  aho  on  account  of  its  usual  attachment  by  an  articulation. 
Here  the  slender  vascular  bundles  oppose  little  resistance  to  lateral 
motion,  while  the  soft  and  usually  cellular  enlargement  favors  it. 
Indeed,  the  efficient  cause  of  the  movement  appears  to  be  exerted 
here,  and  to  be  connected  with  the  unequal  tension  or  turgescence  of 


344  SPECIAL    DIRECTIONS    AND 

the  cells  on  the  two  sides.  "We  might  therefore  expect  more  prompt 
and  obvious  changes  of  position  in  leaves  than  in  stems.  Familiar 
examples  of  the  kind  are  met  with  in  the  altered  nocturnal  position 
of  the  leaves,  &c.  of  many  plants  (often  drooping,  or  folded  as  if  in 
repose),  which  Linnaeus  designated  by  the  fanciful  name  of 

671.  The  Sleep  of  Plants.  This  is  Avell  seen  in  the  foliage  of  the 
Locust  and  of  most  Leguminous  plants,  and  in  those  of  Oxalis,  or 
Wood-Sorrel.  It  is  most  striking  hi  the  leaflets  of  compound  leaves. 
The  nocturnal  position  is  various  in  different  species,  but  uniform  in 
the  same  species,  showing  that  the  phenomenon  is  not  mechanical. 
Nor  is  it  a  passive  state,  for,  instead  of  drooping,  as  do  those  of  the 
common  Locust-tree,  the  leaflets  are  very  commonly  turned  upwards, 
as  those  of  Honey-Locust,  or  upwards  and  forwards,  as  in  the  Sensi- 
tive-Plant, contrary  to  the  position  into  which  they  would  fall  from 
their  own  weight.  De  Candolle  found  that  most  plants  could  be 
made  to  acknowledge  an  artificial  day  and  night,  by  keeping  them  in 
darkness  during  the  day,  and  by  illuminating  artificially  at  night. 
The  sensibility  to  light  appeal's  to  reside  in  the  petiole,  and  not  in 
the  blade  of  the  leaf  or  leaflet ;  for  these  movements  are  similarly 
executed,  when  nearly  the  whole  surface  of  the  latter  is  cut  away. 

672.  The  leaves  of  the  blossom  also  assume  various  positions, 
according  to  the  intensity  and  duration  of  the  light.  Many  expand 
their  blossoms  in  the  morning  and  close  them  towards  evening, 
never  to  be  opened  again,  as  those  of  Cistus,  Portulaca,  and  Spider- 
wort  ;  while  others,  like  the  Crocus,  close  when  the  sun  is  with- 
drawn, but  expand  again  the  following  morning.  On  the  other  hand, 
the  Evening  Primrose,  Silene  noctiflora,  &c.  unfold  their  petals  at 
twilight,  and  close  at  sunrise.  The  White  Water-Lily  (Nymphaea) 
expands  in  the  full  light  of  day,  but  uniformly  closes  near  the  mid- 
dle of  the  afternoon,  and  is  then  usually  withdrawn  beneath  the  sur- 
face of  the  Avater.  The  Morning-Glory  opens  at  the  dawn ;  the 
Lettuce,  and  most  Cichoraceous  plants,  a  few  hours  later,  but  close 
under  the  noonday  sun ;  the  Mirabilis  is  called  Four-o'clock,  because 
opening  nearly  at  that  hour  in  the  afternoon,  and  it  closes  the  next 
morning ;  and  so  of  other  species,  —  each  having  its  own  hour  or 
amount  of  light  in  which  its  blossoms  open  or  close.  Berthelot  men- 
tions an  Acacia  at  Teneriffe,  whose  leaflets  regularly  close  at  sunset 
and  unfold  at  sunrise,  while  its  flowers  close  at  sunrise  and  unfold 
at  sunset.  Although  these  movements,  both  in  leaves  and  blossoms, 
are  undoubtedly  dependent  on  the  light,  they  are  by  no  means  directly 


SPONTANEOUS    MOVEMENTS    IN   PLANTS.  345 

governed  by  it.  The  so-called  sleep  of  the  common  Sensitive  Plant, 
for  instance,  begins  just  before  sunset,  but  its  waking  frequently  pre- 
cedes the  dawn  of  day ;  showing  that  it  is  not  the  mere  amount  of 
the  light  which  governs  the  position,  in  the  manner  of  a  mechanical 
power.* 

673.  Sensible  Movements  from  Irritation.  All  the  changes  of  posi- 
tion already  described  —  like  those  of  the  hands  of  a  clock  or  of 
the  shadow  on  a  dial  —  are  too  slow  for  the  motion  to  be  directly 
seen.  But  a  greater  exaltation  apparently  of  this  common  faculty 
is  observed  in  the  leaflets  of  various  Leguminous  plants,  especially 
of  the  Mimosa  tribe,  which,  when  roughly  touched,  assume  their 
peculiar  nocturnal  position,  or  one  like  it,  by  a  visible  and  sometimes 
a  rapid  movement.  The  Sensitive  Plant  of  the  gardens  (Mimosa 
pudica)  is  a  familiar  instance  of  the  kind,  suddenly  changing  the 
position  of  its  leaflets  on  being  touched  or  jarred,  and  applying 
them  one  over  the  other  close  upon  the  secondary  petiole  ;  if  more 
strongly  irritated,  the  secondary  petioles  also  bend  forward  and 
approach  each  other,  and  the  general  petiole  itself  sinks  by  a  bend- 
ing at  the  articulation  with  the  stem.  Similar  although  less  vivid 
irritability  is  shown  by  the  Mimosa  strigillosa  and  the  Sehrankia  of 
the  Southern  States,  where  the  leaflets  promptly  fold  up  when 
brushed  with  the  hand.  The  most  remarkable  instance  of  the  kind, 
however,  is  presented  by  another  native  plant  of  the  United  States, 
the  Diona?a  muscipula,  or  Venus's  Fly-trap  (Fig.  297,  298)  ;  in  which 
the  touch  even  of  an  insect,  alighting  upon  the  upper  surface  of  the 
outspread  lamina,  causes  its  sides  to  close  suddenly,  the  strong 
bristles  of  the  marginal  fringe  crossing  each  other  like  the  teeth  of 
a  steel-trap,  and  the  two  surfaces  pressing  together  with  considerable 
force,  so  as  to  retain,  if  not  to  destroy,  the  intruder,  Avhose  struggles 
only  increase  the  pressure  which  this  animated  trap  exerts.  This 
most  extraordinary  plant  abounds  in  the  damp,  sandy  savannas  in 
the  neighborhood  of  Cape  Fear  Elver,  from  Wilmington  to  Fayette- 


*  The  odors  of  flowers,  also,  are  sometimes  given  off  continually,  as  in  the 
Orange  and  the  Violet,  or  flowers  may  nearly  lose  their  fragrance  during  the  heat 
of  mid-day,  as  in  most  cases  ;  while  others,  such  as  Pelargonium  triste,  Hesperia 
tristis,  and  most  dingy  flowers,  which  are  almost  scentless  during  the  day,  ex- 
hale a  powerful  fragrance  at  night.  The  night-flowering  Cereus  grandiflorus 
emits  its  powerful  fragrance  at  intervals ;  sudden  emanations  of  odor  being 
given  off  about  every  quarter  of  an  hour,  during  the  brief  period  of  the  expan- 
sion of  the  flower. 


346  SPONTANEOUS   MOVEMENTS   IN   PLANTS. 

ville,  North  Carolina,  where  it  is  exceedingly  abundant ;  but  it  is 
not  elsewhere  found. 

674.  A  familiar,  although  less  striking,  instance  of  the  same  kind 
is  seen  in  the  stamens  of  the  common  Barberry,  which  are  so  excit- 
able, that  the  filament  approaches  the  pistil  with  a  sudden  jerk,  when 
touched  with  a  point,  or  brushed  by  an  insect,  near  the  base  on  the 
inner  side.  The  object  of  this  motion  seems  plainly  to  be  the  dis- 
lodgement  of  the  pollen  from  the  cells  of  the  anther,  and  its  projec- 
tion upon  the  stigma.  But  in  the  Dionrea  it  is  difficult  to  conceive 
what  end  is  subserved  by  the  capture  of  insects.  In  a  species  of 
Stylidium  of  New  Holland,  not  uncommon  in  conservatories,  the 
column,  consisting  of  the  united  stamens  and  styles,  is  bent  over  to 
one  side  of  the  corolla  ;  but  if  slightly  irritated,  it  instantly  springs 
over  to  the  opposite  side  of  the  flower.  These  are  among  the  more 
remarkable  cases  of  the  kind,  but  by  no  means  the  only  ones. 
Anatomical  investigation  brings  to  view  no  peculiarity  in  the  struc- 
ture of  such  plants  which  might  explain  these  movements.  Some 
other  movements,  which  have  been  likened  to  these,  are  entirely 
mechanical ;  as  that  of  the  stamens  of  Kalmia,  where  the  ten  an- 
thers are  in  the  bud  received  into  as  many  pouches  of  the  mono- 
petalous  corolla,  and  are  carried  outwards  and  downwards  when  the 
corolla  expands.  In  this  way  the  slender  filaments  are  strongly  re- 
curved, like  so  many  springs  ;  until  at  length,  when  the  anthers  are 
liberated  by  the  full  expansion  of  the  corolla,  or  by  the  touch  of  a 
large  insect  or  other  extraneous  body,  they  fly  upwards  elastically, 
projecting  a  mass  of  pollen  in  the  direction  of  the  stigma. 

675.  The  twining  of  stems  round  a  support,  and  the  coiling  of 
tendrils,  are  attributed  by  Mold  to  a  dull  irritability ;  and  this  is  the 
most  plausible  explanation  that  has  been  offered.  The  inner  side, 
which  becomes  concave  and  has  smaller  cells,  is  in  this,  as  in  other 
cases,  the  irritable  portion.  "When  a  foreign  body  is  reached,  a 
contraction  of  this  side  causes  the  tendril  partially  to  embrace  the 
support :  this  brings  the  portion  just  above  into  contact  with  it, 
which  is  in  like  manner  incited  to  curve ;  and  so  the  hold  is  secured, 
or  the  twining  stem  continues  to  wind  around  the  support.  In  ten- 
drils this  irritability,  propagated  downward  along  the  concave  side, 
would  appear  to  cause  its  contraction,  which  throws  the  whole  into 
a  spiral  coil,  or,  when  fixed  at  both  ends,  into  two  opposite  spiral 
coils,  thus  approximating  the  growing  stem  to  the  supporting 
body. 


SPONTANEOUS    MOVEMENTS    IN    PLANTS.  347 

676.  In  all  these  cases,  whether  of  slow  or  rapid  change  of  posi- 
tion, the  immediate  cause  of  the  movement,  however  incited,  must 
he  either  the  shortening  of  the  cells  on  the  concave  side,  or  their 
elongation  on  the  convex  side.  The  fact  that  stems  curved  towards 
the  light  tend  to  curve  still  more  when  the  convex  side  is  cut 
away  (669)  points  to  a  contraction  of  the  cells  on  the  concave  side 
as  the  cause  of  the  curvature.  The  elastically  bursting  pods  of  the 
Balsam  or  Touch-me-not  (Impatiens),  &c.  confirm  this  view.  Here 
the  valves  of  the  capsule  curve  inwards  very  strongly  when  liber- 
ated in  dehiscence  ;  and  that  this  is  owing  to  the  shortening  of  the 
cells  of  the  inner  layer,  and  not  to  the  enlargement  or  turgescence  of 
those  of  the  thick  outer  layer,  is  readily  shown  by  gently  paring 
away  the  whole  outer  portion  before  dehiscence  ;  for  the  inner  layer 
when  liberated  still  incurves  and  rolls  itself  up  as  strongly  as  before. 
The  short  valves  at  the  summit  of  the  pod  of  Echinocystis  slowly 
curve  outwards  in  dehiscence ;  here  the  cells  of  the  outer  layer  of 
the  valve  are  longer  and  narrower  than  those  of  the  inner,  and 
the  latter  are  stretched  and  torn  in  opening ;  so  that  here  the  con- 
traction of  the  cells  on  the  side  which  becomes  concave  is  undoubt- 
edly the  cause  of  the  movement.  And  since  muscular  movements 
are  effected  by  the  contraction  of  the  cells  which,  placed  end  to  end, 
compose  a  muscular  fibril,  Ave  may  suspect  that  vital  movements 
generally,  both  in  vegetables  and  in  animals,  are  so  far  analogous, 
that  they  are  brought  about  in  the  same  general  way,  viz.  by  the 
shortening  of  cells.  Even  the  opening  and  closing  of  the  stomata 
of  the  leaves  (268)  appear  to  be  controlled  by  the  vital  force,  and 
to  be  effected  by  a  self-caused  change  in  the  form  of  the  guardian 
cells.  How  the  light,  or  external  irritation,  or  any  other  influence, 
acts  in  inciting  this  change  of  form  of  the  cells  of  some  part  of  a 
plant,  we  know  no  more,  and  no  less,  than  we  know  how  a  nerve,  or 
an  electrical  current,  acts  upon  a  muscle  of  an  animal  to  bring 
about  the  contraction  or  change  of  shape  of  its  component  cells. 
If  animals  make 

677.  Spontaneous  or  Automatic  Movements,  so  also  do  some  plants 

execute  brisk  and  repeated  movements  irrespective  of  extraneous 
force,  or  even  of  extraneous  excitation,  and  which,  indeed,  are  ar- 
rested by  the  touch.  An  instance  of  such  spontaneous  and  contin- 
ued motion,  of  the  most  remarkable  kind,  is  furnished  by  the  trifoli- 
olate  leaves  of  Desmodium  gyrans,  an  East-Indian  Leguminous  plant. 
The  terminal  leaflet  does  not  move,  except  to  change  from  the 


348 


SPONTANEOUS    MOVEMENTS    IN    PLANTS. 


diurnal  to  the  nocturnal  position,  and  the  contrary ;  but  the  lateral 
ones  are  continually  rising  and  falling,  both  day  and  night,  by  a  suc- 
cession of  little  jerks,  like  the  second-hand  of  a  time-keeper ;  the 
one  rising  Avhile  the  other  falls.  Exposure  to  cold,  or  cold  water 
poured  upon  the  plant,  stops  the  motion,  which  is  immediately  re- 
newed by  warmth.  The  late  Dr.  Baldwin  is  said  by  Nuttall  to 
have  Avitnessed  the  same  thing  in  our  oavii  Desmodium  cuspidatum, 
in  Georgia ;  but  the  obseiwation  has  never  been  confirmed.  In 
several  tropical  Orchideous  plants,  and  especially  in  a  species  of 
Megaclinium,  the  loAver  petal,  or  labellum,  executes  similar  spontane- 
ous moA'ements,  A\rith  great  freedom  and  pertinacity.  Such  phenom- 
ena, occurring  as  they  do  in  Phamogamous  plants  of  ordinary  struc- 
ture may  serve  to  render  more  credible  the  true  vegetable  character 
of  the 
G78.  Free  Movements  of  the 

SporCS  of  Algae,  and  the  cor- 
puscles or  spiral  filaments  of 
the  antheridia  of  most  Cryp- 
togamous  plants,  already  re- 
ferred to  (G59  -  G63).  The 
spores  of  most  of  the  lower 
Algas  are  noAV  knoAvn  to  ex- 
hibit this  peculiar  activity 
at  the  time  of  their  discharge 
from  the  parent  cell,  when, 
for  some  moments,  or  usual-  i  ^  'I'// 
ly  for  several  hours,  they 
behave  like  mfusory  ani- 
mals, executing  spontaneous 
moA-ements  in  the  water, 
until  they  are  about  to  ger- 
minate. This  singular  move- 
ment Avas  first  detected  many 
years     ago     in     Vaucheria 

FIG.  636.  Fruiting  end  of  a  plant  of  A'aucheria  geminata  (after  Thuret) ;  one  of  the 
branches  still  containing  its  spore.  637.  Moving  spore  just  escaped  from  the  apex  of  the 
other  branch  ;  the  ciliary  apparatus  seen  oyer  the  whole  surface.    638.  Spore  in  germination. 

FIG.  639-642.  Successive  steps  in  the  germination  of  (Edogoniuin  (Conferva)  vesicata. 
643.  The  plant  developed  into  a  series  of  cells,  four  of  which  display  the  successive  steps  in  the 
formation  of  a  spore.  644.  The  locomotive  spore  with  its  vibratile  cilia  (copied  from  Thuret). 
AVhen  the  movement  ceases,  and  it  begins  to  germinate,  it  appears  as  in  639.  (The  antheridia 
or  fertilizing  apparatus  of  these  plants  were  not  known  when  these  figures  were  made.) 


SPONTANEOUS   MOVEMENTS   IN   PLANTS.  349 

(Fig.  89,  G36).  Immediately  on  its  discharge  from  the  mother 
plant  the  spore  begins  to  move  freely  in  the  "water,  and  continues  to 
do  so  for  some  hours,  when  it  fixes  itself  and  begins  to  grow  (Fig. 
638).  Its  movements,  moreover,  like  those  of  the  antheridial  fila- 
ments or  corpuscles,  may  be  enfeebled  or  arrested  by  the  application 
of  a  weak  solution  of  opium  or  chloroform.  Through  these  means 
it  has  been  ascertained  that  they  are  caused  by  the  vibrations  of 
minute  cilia  which  cover  the  surface,  which  are  rendered  visible 
by  thus  enfeebling  their  movement,  and  which  exhibit  the  closest 
resemblance  to  the  vibratile  cilia  of  animals,  especially  those  of  the 
polygastric  animalcules.  In  the  Conferva  tribe  generally  the  vibra- 
tile cilia  occupy  one  end  of  the  spore,  and  are  in  some  cases  numer- 
ous (as  in  Fig.  644),  in  others  only  two  or  three  in  number.  The 
spores  are  small,  and  of  about  the  same  specific  gravity  as  the  water 
in  which  they  live,  so  that  a  slight  force  suffices  to  propel  them. 

679.  Locomotion  of  Adult  Microscopic  Plants.    The  spores  of  Vau- 

cheria  and  the  like,  becoming  quiescent  before  germination,  grow 
into  fixed  thread-like  plants  of  considerable  size,  endowed  with  no 
greater  degree  of  motivity  than  ordinary  vegetables.  A  multitude 
of  still  simpler  Algre,  however,  swarm  in  every  pool  or  stream,  so 
minute  in  size  as  to  be  individually  totally  invisible  to  the  naked 
eye  (most  of  them  when  full  grown  are  very  much  smaller  than  the 
spores  of  Vaucheria,  &c.)  ;  and  these  are  endowed,  even  at  maturity, 
with  such  powers  of  locomotion  that  their  vegetable  character, 
although  now  well  made  out,  was  long  in  question  on  this  account 
alone.  Of  this  kind  are  the  various  species  of  Oscillaria  (Fig.  84), 
so  named  from  the  writhing  movement  they  exhibit,  the  Desmidi- 
acere,  to  which  Closterium  (Fig.  631)  belongs,  and  the  nearly 
allied  Diatomacea?,  —  the  lowest,  minutest,  and  the  most  freely 
moving  of  plants,  but  clearly  members  of  the  vegetable  kingdom 
notwithstanding.  These  execute  free  movements  of  translation,  in 
some  cases  slow,  in  others  rapid ;  but  the  mechanism  of  the  motion 
is  still  unknown. 

680.  Not  only,  therefore,  do  plants  generally  manifest  impressi- 
bility or  sensitiveness  to  external  agents,  and  execute  more  or  less 
decided,  though  slow,  movements ;  but  many  species  of  the  higher 
grades  exhibit  certain  vivid  motions,  either  spontaneous  or  in  conse- 
quence of  extraneous  irritation  ;  while  the  lowest  tribes  of  aquatic 
plants,  as  they  diminish  in  size  and  in  complexity  of  organization, 
habitually  execute,  at  some  period  at  least,  varied  spontaneous  move- 

30 


350  SPONTANEOUS    MOVEMENTS    IN   PLANTS. 

merits,  which  we  are  unable  to  distinguish  in  character  from  those  of 
the  lowest  animals.  It  is  at  their  lowest  confines,  accordingly,  that 
the  vegetable  and  the  animal  kingdoms  approach  or  meet,  and  even 
seem  to  blend  their  characters. 

G81.  When  Ave  consider  that  the  excitability  of  sensitive  plants 
is  often  transmitted,  as  if  by  a  sort  of  sympathy,  from  one  part  to 
another ;  that  it  is  soon  exhausted  by  repeated  excitation  (as  is 
certainly  the  case  in  Dionoea,  the  Sensitive-Plant,  &c),  to  be  re- 
newed only  after  a  period  of  repose ;  that  all  plants  require  a 
season  of  repose  ;  that  they  consume  their  products  and  evolve  heat 
under  special  circumstances  with  the  same  results  as  in  the  animal 
kingdom  (Chap.  VII.)  ;  that,  as  if  by  a  kind  of  instinct,  the  various 
organs  of  the  vegetable  assume  the  positions  or  the  directions  most 
favorable  to  the  proper  exercise  of  their  functions  and  the  supply  of 
their  wants,  to  this  end  surmounting  intervening  obstacles  ;  when 
we  consider  in  this  connection  the  still  more  striking  cases  of  spon- 
taneous motion  that  the  lower  Alga;  exhibit ;  and  that  all  these 
motions  are  arrested  by  narcotics,  or  other  poisons,  —  the  narcotic 
and  acrid  poisons  even  producing  etfects  upon  vegetables  respectively 
analogous  to  their  different  effects  upon  the  animal  economy ;  we 
cannot  avoid  attributing  to  plants  a  vitality  and  a  power  of  "  making 
movements  tending  to  a  determinate  end,"  not  different  in  nature, 
perhaps,  from  those  of  the  lowest  animals.  Probably  life  is  essen- 
tially the  same  in  the  two  kingdoms  ;  and  to  vegetable  life  faculties 
are  superadded  in  the  lower  animals,  some  of  which  are  here  and 
there  not  indistinctly  foreshadowed  in  plants. 

682.  The  essential  differences  between  plants  and  animals  were 
enumerated  at  the  commencement  of  this  work  (1G),  and  have  been 
illustrated  in  its  progress.  Distinct  as  are  the  general  structure 
and  the  offices  of  the  two  great  kinds  of  organized  beings,  it  is  still 
doubtful  whether  the  discrimination  is  absolute,  or  whether  the 
functions  of  the  vegetable  and  the  animal  may  not,  in  some  micro- 
scopic organisms,  be  imposed  upon  the  same  individual. 


PART   II. 
SYSTEMATIC    BOTANY. 


683.  In  the  preceding  chapters  plants  have  been  considered  in 
view  of  their  structure  and  action.  And  when  different  plants  have 
been  referred  to  and  their  diversities  noticed,  it  has  been  in  eluci- 
dation of  their  morphology,  —  of  the  exuberantly  varied  forms  or 
modifications  under  which  the  simple  common  plan  of  vegetation  is 
worked  out,  as  it  were,  in  rich  detail.  The  vegetable  kingdom,  that 
is,  vegetation  taken  as  a  great  whole,  presents  to  our  view  an  im- 
mense number  of  different  kinds  of  plants,  more  or  less  resembling 
each  other,  more  or  less  nearly  related  to  each  other.  It  is  the 
object  of  Systematic  Botany  to  treat  of  plants  as  members  of  a 
system,  or  orderly  parts  of  a  whole,  —  and  therefore  to  consider 
them  as  to  their  kinds,  marked  by  differences  and  resemblances,  and 
to  contemplate  the  relations  which  the  kinds,  or  individual  members 
of  the  great  whole,  sustain  to  each  other.  To  tins  end  the  botanist 
classifies  them,  so  as  to  exhibit  their  relationships,  or  degrees  of 
resemblance,  and  expresses  these  in  a  systematic  arrangement  or 
classification,  —  designates  them  by  appropriate  appellations,  and 
distinguishes  them  by  clear  and  precise  descriptions  in  scientific  lan- 
guage ;  so  that  not  only  may  the  name  and  place  in  the  system,  the 
known  properties,  and  the  whole  history  of  any  given  plant,  be  read- 
ily and  surely  obtained  by  the  learner,  but  likewise  an  interesting 
view  may  be  obtained  of  the  general  scheme  or  plan  of  the  Cre- 
ator in  the  Vegetable  World. 

G84.  Our  present  endeavor  will  be  to  explain  the  general  prin- 
ciples of  natural-history  classification,  and  the  foundation,  or  facts 
in  nature,  upon  which  it  rests,  and  then  cursorily  to  show  how  these 
are  applied  to  the  actual  arrangement  of  the  known  species  of 
plants. 


352  PRINCIPLES    OF    CLASSIFICATION. 

CHAPTER    I. 

OF   THE   PRINCIPLES   OF   CLASSIFICATION. 

685.  Plants  and  animals  —  the  members  of  the  organic  king- 
doms of  nature  —  exist  as  individuals  (13),  of  definite  kinds,  each 
endowed  with  the  characteristic  power  of  producing  like  individuals 
and  so  of  continuing  the  succession.  The  different  sorts  (1.)  are  re- 
produced true  to  their  essential  characteristics  from  generation  to 
generation  ;  and  (2.)  they  exhibit  unequal  and  very  various  degrees 
of  resemblance  or  of  dissimilarity  among  themselves.  These  simple 
propositions  lie  at  the  foundation  of  all  classification  and  system  in 
natural  history.  Upon  the  first  rests  the  idea  of  species  ;  upon  the 
second  that  of  genera,  orders,  and  all  groups  higher  than  species. 

686.  Individuals.  The  idea  of  individuality  is  derived  from  man 
and  ordinary  animals,  and  thence  naturally  extended  to  vegetables. 
Individuals  are  beings,  owing  their  existence  and  their  characteris- 
tics to  similar  antecedent  beings,  and  composed  of  parts  which 
together  constitute  an  independent  whole,  indivisible  except  by  mu- 
tilation. Individuality  is  perfectly  exemplified  in  all  the  higher  and 
most  of  the  lower  animals,  which  multiply  by  sexual  propagation 
only,  and  in  which  the  offspring,  or  the  ovum,  early  separates  from 
tbe  parent ;  but  it  is  incompletely  realized  in  those  animals  of  the 
lower  grade  which  are  propagated  by  buds  or  offshoots  as  Avell  as 
by  ova,  and  where  the  offspring  may  remain  more  or  less  intimately 
connected  with  the  parent.  Still  more  is  this  so  in  plants,  which 
in  every  grade  are  or  may  be  propagated  by  buds  or  offshoots ; 
which  in  vegetation  develop  an  indefinite  number  of  similar  parts  ; 
which  produce  branches  like  the  parent  plant,  and  capable  either  of 
continuing  to  grow  in  connection  with  it,  or  of  becoming  independent 
(232).  The  individual  jdant,  therefore,  is  evidently  not  a  simple 
and  true  individual  in  the  proper  sense  of  the  word,  —  in  the  sense 
that  an  ordinary  animal  is.  A  kind  of  social  or  corporate  individu- 
ality in  the  complex  radiated  animals  often  gives  a  certain  limita- 
tion and  shape  to  the  congeries  or  polypidom,  and  in  many  of  them 
even  subordinates  certain  parts  to  the  common  whole,  assigning  to 
them  special  functions  for  the  common  weal :  and  this  is  universally 
and  more  strikingly  the  case  with  plants,  except  the  very  simplest. 


INDIVIDUALS.  353 

So  that  for  practical  purposes,  and  in  a  loose,  general  sense,  we 
take  the  whole  plant  as  an  individual,  so  long  as  it  forms  one  con- 
nected mass,  and  no  longer.  But  in  a  philosophical  view  we  cannot 
well  regard  this  congeries  as  the  true  vegetable  individual. 

687.  Accordingly  many  botanists  (of  whom  are  Thouars  at  the 
beginning  of  the  present  century,  and  Braun  *  at  the  present  day) 
regard  as  the  true  individual  the  shoot,  or  simple  axis  with  its  foli- 
age, &c,  whether  this  be  the  primary  stem  with  its  roots  implanted 
in  the  soil,  or  a  branch  implanted  on  the  stem.  This  view  simpli- 
fies our  conception  of  a  vegetable,  but  is  itself  open  to  all  the  objec- 
tions it  raises  against  the  individuality  of  the  plant  as  a  whole.  For 
just  as  the  herb,  shrub,  or  tree  is  divisible  into  shoots  or  series  of 
similar  axes,  so  the  shoot  is  divisible  into  similar  component  parts, 
or  phytons  (163),  indefinitely  repeated,  and  which  may  equally  give 
rise  to  independent  plants.  Those  philosophical  naturalists,  there- 
fore, who  find  no  stable  ground  in  this  position,  are  forced  towards 
one  of  two  opposite  extremes.  Some,  justly  viewing  sexual  repro- 
duction as  of  the  highest  import,  are  led  to  regard  the  whole  vege- 
tative product  of  a  seed  as  theoretically  constituting  one  individual, 
whether  the  successive  growths  remain  united,  or  whether  they  form 
a  thousand  or  a  million  of  vegetables,  as  may  often  happen.  Ac- 
cording to  this  view,  all  the  Weeping-Willow  trees  of  this  country 
are  parts  of  one  individual ;  and  most  of  our  Potato  plants  must  be- 
long to  one  multitudinous  individual,  while  others  wholly  similar,  but 
freshly  grown  from  seed,  are  each  individuals  of  themselves ;  —  a 
view  which  apparently  amounts  to  an  absurdity  in  terms  and  in  fact. 
Others,  following  out  the  idea  mentioned  above,  and  laying  the  main 
stress  upon  simplicity  and  indivisibility,  rather  than  upon  tendency 
to  separation,  regard  the  phyton  in  ordinary  plants,  and  the  cell  in 
those  of  lowest  grade,  as  on  the  Avhole  best  answering,  in  the  vege- 
table kingdom,  to  the  simple  individual  in  the  animal.  But  this  is 
merely  a  question  of  greater  or  less  analogy.  For  the  individual,  in 
the  proper  sense  of  the  term,  is  more  or  less  confluent  into  a  vegeta- 
tive cycle  in  all  plants,  and  in  many  of  the  lower  animals,  and  attains 
full  realization  only  in  the  higher  grades  of  organized  existence. 


*  See  his  elaborate  treatise,  On  the  Vegetable  Individual  in  its  Relation  to  Species 
(of  which  a  translation  from  the  German,  by  C.  F.  Stone,  was  published  in  the 
American  Journal  of  Science  and  the  Arts,  vols.  19  and  20,  1855),  for  the  com- 
pletest  development  of  this  view,  and  for  the  history  of  the  subject  generally. 
30* 


354  PRINCIPLES    OF    CLASSIFICATION. 

688.  But,  whatever  it  may  be  which  we  practically  or  philosophi- 
cally regard  as  the  vegetable  individual,  it  is  evident  that  plants  as 
well  as  animals  occur  in  a  continued  succession  of  organisms  or 
beings  which  stand  in  the  relation  of  parent  and  offspring.  Each 
particular  sort  is  a  chain,  of  which  the  individuals  are  the  links. 
To  this  chain,  or  (as  expressed  by  Linnaeus)  this  perennial  succes- 
sion of  individuals,  the  natural-historian  applies  the  name  of 

689.  Species  (14).  Every  one  knows  that  the  several  sorts  of 
plants  and  animals  steadily  reproduce  themselves,  or,  in  other  words, 
keep  up  a  succession  of  essentially  similar  individuals,  and  under 
favorable  circumstances  increase  their  numbers.  Each  particular 
kind  of  cultivated  plant  or  domesticated  animal  is  represented  before 
our  eyes  in  a  mass  of  individuals,  which  Ave  know  from  observation 
to  a  certain  extent,  and  from  necessary  inference,  have  sprung 
from  the  same  stock.  And  common  observation  has  led  people 
everywhere  to  expect  that  the  different  sorts  will  continue  true  to 
their  kind,  or  at  least  to  conclude  that  the  different  sorts  of  plants 
or  of  animals  do  not  shade  off  one  into  another  by  insensible  grada- 
tions, like  the  colors  of  the  rainbow,  as  would  have  been  the  case  if 
there  were  not  distinct  kinds  at  the  beginning,  and  if  their  distinc- 
tions were  not  kept  up,  unmingled,  and  transmitted  essentially  un- 
altered, from  generation  to  generation.  So  we  naturally  assume  that 
the  Creator  established  a  definite,  although  a  vast,  number  of  types 
or  sorts  of  plants  and  animals,  and  endowed  them  with  the  faculty 
of  propagation  each  after  its  kind ;  and  that  these  have  so  continued 
unchanged  in  all  their  essential  characteristics.  Out  of  these  gen- 
eral observations  and  conceptions  the  idea  of  species  must  have  origi- 
nated ;  from  them  we  deduce  its  scientific  definition.  Namely,  that 
the  species  is,  abstractly,  the  type  or  original  of  each  sort  of  plant, 
or  animal,  thus  represented  in  time  by  a  perennial  succession  of  like 
individuals,  or,  concretely,  that  it  is  the  sum  of  such  series  or  con- 
geries of  individuals  ;  and  that  all  the  descendants  of  the  same  stock, 
and  of  no  other,  compose  one  species.  And,  conversely,  as  we  can 
never  trace  back  the  genealogy  far,  Ave  naturally  infer  community 
of  origin  from  fraternal  resemblance ;  that  is,  Ave  refer  to  the  same 
species  those  indiA'iduals  which  are  as  much  alike  as  those  are 
Avhich  Ave  knoAV  to  have  sprung  from  the  same  stock.* 

*  We  use  the  word  stock  advisedly,  (and  in  one  of  its  proper  meanings,  that 
of  the  original  or  originals  of  a  lineage,)  to  avoid  the  assertion  or  denial  of  the 


SPECIES    AND    VARIETIES.  355 

690.  Specific  identity  is  not  of  course  inferred  from  every  strongly 
marked  resemblance  ;  for  the  resemblance  may  be  only  that  of  genus, 
and  individuals  so  related  are  inferred  not  to  have  had  fi  common 
origin.  Nor  is  it  denied  on  account  of  every  difference  ;  for  individu- 
als of  the  same  stock  may  differ  considerably ;  in  fact,  no  two  plants 
are  exactly  alike,  any  more  than  two  men  are.  Such  differences 
when  they  become  distinctly  marked  give  rise  to 

691.  Varieties.  If  two  seeds  from  the  same  pod  are  sown  in  dif- 
ferent soils,  and  submitted  to  different  conditions  as  respects  heat, 
light,  and  moisture,  the  plants  that  spring  from  them  will  show 
marks  of  this  different  treatment  in  their  appearance.  Such  differ- 
ences are  continually  arising  in  the  natural  course  of  things,  and  to 
produce  and  increase  them  artificially  is  one  of  the  objects  of  culti- 
vation. Such  variations  in  nature  are  transient ;  the  plant  often 
outlasting  the  cause  or  outgrowing  its  influence,  or  else  perishing 
from  the  continued  and  graver  operation  of  the  modifying  influ- 
ences. But  in  the  more  marked  varieties  which  alone  deserve 
the  name,  the  cause  of  the  deviation  is  occult  and  constitutional ;  the 
deviation  occurs  we  know  not  Avhy,  and  continues  throughout  the 
existence  and  growth  of  the  herb,  shrub,  or  tree,  and  consequently 
through  all  that  proceeds  from  it  by  propagation  from  buds,  as  by  off- 
sets, layers,  cuttings,  grafts,  &c.  In  this  way  choice  varieties  of  Ap- 
ples, Pears,  Potatoes,  and  the  like,  are  multiplied  and  perpetuated. 

692.  Since  the  progeny  inherits  or  tends  to  inherit  all  the  char- 
acters and  properties  of  the  parent,  constitutional  varieties  must  have 
a  tendency  to  be  reproduced  by  seed,  —  a  tendency  which  might 
often  prevail,  within  certain  limits,  over  that  general  influence  which 
would  remand  the  variety  to  the  normal  state,  were  it  not  for  the 
commingling  which  so  commonly  occurs  in  nature,  through  the  cas- 
ual fertilization  of  the  ovules  of  one  individual  by  the  pollen  of  other 
individuals  of  the  same  species.     By  assiduously  pursuing  the  oppo- 


origin  of  each  species  from  a  single  individual  or  a  single  pair,  —  a  question 
which  science  does  not  furnish  grounds  for  deciding.  It  is  evidently  more 
simple  to  assume  the  single  origin,  where  there  is  no  presumption  to  the  con- 
trary, as  there  may  be  in  the  case  of  triceeious  or  of  organically  associated  plants 
or  animals  ;  but  the  contrary  supposition  does  not  affect  our  idea  of  species,  if 
we  suppose  the  originals  to  have  been  as  much  alike  as  individuals  proceeding 
from  the  same  parent  are,  and  to  have  had  a  common  birthplace.  The  investi- 
gation of  the  geographical  distribution  of  plants  more  and  more  favors  the  idea 
of  the  dissemination  of  each  species  from  a  centre  of  its  own. 


356  PRINCIPLES    OP   CLASSIFICATION. 

site  course  in  domesticated  plants,  that  is,  by  constantly  insuring  the 
fertilization  of  the  ovules  of  a  marked  variety  by  the  pollen  of  the 
same,  and  by  saving  seed  only  from  such  of  the  resulting  progeny  as 
possess  the  desired  peculiarity  in  the  highest  degree,  and  so  on  for 
several  generations,  it  would  appear  that 

693.  Races,  viz.  varieties  whose  characteristics  are  transmissible 
by  seed  with  considerable  certainty,  may  generally  be  produced.  Of 
this  kind  are  the  particular  sorts  of  Indian  Corn,  Rye,  Cabbage, 
Lettuce,  Radishes,  &c,  and  indeed  of  nearly  all  our  varieties  of  culti- 
vated annual  and  biennial  esculent  plants,  as  well  as  of  several  per- 
ennials, many  of  which  have  been  fixed  through  centuries  of  domes- 
tication. What  is  now  taking  place  with  the  Peach  in  this  country 
may  convince  us  that  races  may  be  developed  in  trees  as  well  as  in 
herbs,  and  in  the  same  manner ;  and  that  the  reason  why  most  of 
our  cultivated  races  are  annuals  or  biennials  is  because  these  can 
be  perpetuated  in  no  other  way,  and  because  the  desired  result 
is  obtainable  in  fewer  years  than  in  shrubs  or  trees.  Although 
races  hardly  exist  independently  of  man,  he  cannot  be  said  to  origi- 
nate their  peculiarities,  nor  is  it  known  how  they  originate.  The 
sports,  as  the  gardener  calls  them,  appear  as  it  were  accidentally 
in  cultivated  plants.  The  cultivator  merely  selects  the  most  promis- 
ing sorts  for  preservation,  leaving  the  others  to  their  fate.  By  par- 
ticular care  he  develops  the  characteristic  feature,  and  strengthens 
and  fixes,  in  the  manner  already  explained,  the  tendency  to  become 
hereditary,  so  securing  the  transmissibility  of  the  variety  as  long  as 
he  takes  sufficient  care  of  it.  If  not  duly  cared  for,  they  dwindle  and 
lose  their  peculiarities,  or  else  perish  ;  if  allowed  to  mix  with  normal 
forms,  they  revert  to  the  common  state  of  the  species.  "Were  culti- 
vation to  cease,  all  these  valued  products  of  man's  care  and  skill 
would  doubtless  speedily  disappear ;  the  greater  part,  perhaps,  would 
perish  outright ;  the  remainder  would  revert,  in  a  few  generations 
of  spontaneous  growth,  to  the  character  of  the  primitive  stock. 

694.  Although  man  has  no  power  to  create  the  peculiarities  of 
such  varieties,  he  may  manage  so  as  not  only  largely  to  increase 
them,  but  also  to  combine  the  peculiarities  of  widely  different  varie- 
ties of  a  species,  and  thereby  produce  novel  results.  This  is  effected 
by  Cross-breeding,  i.  e.  by  fertilizing  the  pistil  of  one  variety  Avith  the 
pollen  of  another  variety  of  the  same  species.  In  this  way  most 
esteemed  new  varieties  of  flowers  and  fruits  are  originated,  which 
combine  the  separate  excellences  of  both  parents.     The  cultivator 


RACES,    HYBRIDS,    ETC.  357 

often  proceeds  one  step  farther,  in  certain  cases,  and  gives  rise  to  a 
different  kind  of  cross-breeds,  viz. 

695.  Hybrids.  These  are  cross-breeds  from  different  but  nearly 
related  species.  It  is  well  known  that,  by  proper  precautions,  the 
pistil  of  a  flower  of  one  species  may  often  be  fertilized  by  the  pollen 
of  another  of  a  similar  constitution,  and  that  the  plants  raised  from 
the  seeds  so  produced  combine  the  characters  and  properties  of 
both  parents.  Some  kinds,  such  as  Azaleas  and  Pelargoniums,  hy- 
bridize very  readily ;  in  others  hybridism  is  effected  with  difficulty 
between  nearly  related  species.  The  gardener  produces  hybrids 
among  most  of  Ms  favorite  plants,  and  variously  cross-breeds  and 
mingles  them,  so  as  to  confuse  the  limits  of  many  cultivated  species. 
But  in  nature  hybrids  rarely  occur.  Not  more  than  fifty  wild  kinds 
are  clearly  known  as  of  continued  or  frequent  occurrence.  Others 
may  perhaps  be  originated  from  time  to  time ;  but  their  existence 
is  transient.  For  hybrids  are  generally,  if  not  always,  sterile,  and 
therefore  incapable  of  perpetuation  by  seed.  But  their  ovules  may 
be  fertilized  by  the  pollen  of  either  of  their  parents,  when  the 
progeny  reverts  to  that  species,  probably  retaining,  however,  some 
traces  of  the  mixture,  unless  this  should  be  obliterated  by  successive 
fertilizations  from  individuals  of  the  same  parent  species.  It  is 
probable  that  cross-fertilization  between  different  individuals  of  the 
same  species  is  more  common  than  is  generally  supposed,  and  that 
it  is  one  of  Nature's  means  for  repressing  variation.  On  the  other 
hand,  continued  self-fertilization  (or  breeding  in  and  in)  is  almost 
sure  to  perpetuate,  as  well  as  farther  to  develop,  individual  peculiari- 
ties, i.  e.  those  of  variety  or  race. 

696.  However  plants  may  be  modified  by  art  and  man's  device, 
the  systematic  botanist  proceeds  upon  the  ground  that  the  distinc- 
tions between  species,  whether  small  or  great,  are  real,  and  in  nature 
are  permanent,  —  that  variation,  wide  as  it  may  be,  is  naturally  re- 
stricted within  certain  limits.  And  this  appears  to  be  true.  As  dis- 
tinctions subordinate  to  species  are  in  nature  both  indefinite  and 
transitory,  these,  however  important  to  the  cultivator,  are  of  little 
account  with  the  systematic  botanist. 

697.  Species  are  the  true  subjects  of  classification.  And  the  end 
and  aim  of  systematic  botany  is  to  ascertain  and  to  express  their 
relationship  to  each  other.  The  whole  ground  in  nature  for  the 
classification  of  species  is  the  obvious  fact  that  species  resemble 
or  differ  from  each  other  unequally  and  in  extremely  various  de- 


358  PRINCIPLES    OF   CLASSIFICATION. 

grees.  If  this  were  not  so,  or  if  related  species  differed  one  from 
another  hy  a  constant  quantity,  so  that,  when  arranged  according 
to  their  resemblances,  the  first  differed  from  the  second  about  as 
much  as  the  second  from  the  third,  and  the  third  from  the  fourth, 
and  so  on  thi-oughout, —  then,  with  all  the  diversity  in  the  vege- 
table kingdom  there  actually  is,  there  could  be  no  natural  founda- 
tion for  their  classification.  The  multitude  of  species  would  render 
it  necessary  to  classify  them,  but  the  classification  would  be  wholly 
artificial  and  arbitrary.  The  actual  constitution  of  the  vegetable 
kingdom,  however,  as  appears  from  observation,  is,  that  some  species 
resemble  each  other  very  closely  indeed,  others  differ  as  widely  as 
possible,  and  between  these  the  most  numerous  and  the  most  various 
grades  of  resemblance  or  difference  are  presented,  but  always  with 
a  manifest  tendency  to  compose  groups  or  associations  of  resembling 
species,  —  groups  the  more  numerous  and  apparently  the  less  defi- 
nite in  proportion  to  the  number  and  the  nearness  of  the  points  of 
resemblance.  These  various  associations  the  naturalist  endeavors  to 
express,  as  far  as  is  necessary  or  practicable,  by  a  series  of  generali- 
zations, —  of  which  the  lower  or  particular  are  included  in  the 
higher,  —  based  on  the  more  striking,  or  what  he  deems  the  most 
important  (i.  e.  the  most  definite  or  least  exceptional)  points  of  re- 
semblance of  several  grades.  Linnaeus  and  the  naturalists  of  his 
day  mainly  recognized  three  grades  of  association,  or  groups  supe- 
rior to  species,  viz.  the  genus,  the  order,  and  the  class  ;  and  these  are 
still  the  principal  members  of  classification.     Of  these 

698.  Genera  (plural  of  Genus)  are  the  more  particular  or  special 
groups  of  related  species.  They  are  groups  of  species  which  are 
most  alike  in  all  or  most  respects,  —  which  are  constructed,  so  to 
say,  upon  the  same  particular  model,  with  only  circumstantial  dif- 
ferences in  the  details.  They  are  not  necessarily  nor  generally  the 
lowest  definable  groups  of  species,  but  are  the  lowest  most  clearly 
defoiable  groups  which  the  botanist  recognizes  and  accounts  worthy 
to  bear  the  generic  name  ;  for  the  name  of  the  genus  with  that  of 
the  species  added  to  it  is  the  scientific  appellation  of  the  plant  or 
animal.  Constituted  as  the  vegetable  and  animal  kingdoms  are,  the 
recognition  of  genera,  or  groups  of  kindred  species,  is  as  natural  an 
operation  of  the  mind  as  is  the  conception  of  species  from  the  asso- 
ciation of  like  individuals.  This  is  because  many  genera  are  so 
strongly  marked,  or  at  least  appear  to  be  so,  as  far  as  ordinary  ob- 
servation extends.     Every  one  knows  the  Rose  genus,  composed  of 


GENERA    AND    ORDERS.  359 

the  various  species  of  Roses  and  Sweetbriers  ;  the  Bramble  genus, 
comprising  Raspberries,  &c,  is  popularly  distinguished  to  a  cer- 
tain extent ;  the  Oak  genus  is  distinguished  from  the  Chestnut  and 
the  Beech  genus,  &c. :  each  is  a  group  of  species  whose  mutual 
resemblance  is  greater  than  that  of  any  one  of  them  to  any  other 
plant.  The  number  of  species  in  such  a  group  is  immaterial,  and 
in  fact  is  very  diverse.  A  genus  may  be  represented  by  a  single 
known  species,  when  its  peculiarities  are  equivalent  in  degree  to 
those  which  characterize  other  genera,  —  a  case  which  often  occurs  ; 
although  if  this  were  generally  so,  genus  and  species  would  be 
equivalent  terms.  If  only  one  species  of  Oak  were  known,  the  Oak 
genus  would  have  been  as  explicitly  discerned  as  it  is  now  that  the 
species  amount  to  two  hundred ;  it  would  have  been  equally  distin- 
guished by  its  acorn  and  cup  from  the  Chestnut,  Beech,  Hazel,  &c. 
Familiar  illustrations  of  genera  in  the  animal  kingdom  are  furnished 
by  the  Cat  kind,  to  which  belong  the  domestic  Cat,  the  Catamount, 
the  Panther,  the  Lion,  the  Tiger,  the  Leopard,  &c. ;  and  by  the 
Dog  kind,  which  includes  with  the  Dog  the  different  species  of 
Foxes  and  Wolves,  the  Jackal,  &c.  The  languages  of  the  most 
barbarous  people  show  that  they  have  recognized  such  groups. 
Naturalists  merely  give  to  them  a  greater  degree  of  precision,  and 
indicate  what  the  points  of  agreement  are. 

699.  If  all  such  groups  were  as  definite  and  as  conspicuously 
marked  out  as  those  from  which  illustrations  are  generally  taken, 
genera  might  be  as  natural  as  species.  But  unfortunately  the  pure- 
ly popular  genera  are  comparatively  few,  and  although  often  cor- 
rectly founded  by  the  unscientific,  yet  they  are  as  frequently  wrongly 
limited,  or  based  upon  fanciful  resemblances.  Popular  nomencla- 
ture, embodying  the  common  ideas  of  people,  merely  shows  that 
generic  groups  are  recognizable  in  a  considerable  number  of  cases, 
but  not  that  the  whole  vegetable  or  the  whole  animal  kingdom  is 
divisible  into  a  definite  number  of  such  groups  of  equally  or  some- 
what equally  related  species.  Whether  this  proves  to  be  so  or  not, 
and  whether  genera  are  actually  limited  groups  throughout,  this  is 
not  the  place  to  consider.  Suffice  it  to  say,  that  there  is  a  ground 
in  nature  for  genera,  and  that  the  naturalist  is  obliged  to  treat  them, 
for  systematic  purposes,  as  strictly  definite  groups  of  species.  While 
genera  represent  the  closer  relationships  of  species, 

700.  Orders  or  Families  (as  they  are  interchangeably  called  in 
botany)  express  remoter  relationships  or  more  general  resemblances. 


360  PRINCIPLES    OF   CLASSIFICATION. 

They  are  groups  of  kindred  genera,  or  rather  genera  of  a  higher 
grade.  For  example,  Oaks,  Chestnuts,  Beeches,  Hazels,  and  Horn- 
beams constitute  so  many  genera,  which,  although  quite  distinct,  have 
so  strong  a  family  likeness,  and  are  so  much  alike  in  their  general 
structure  and  properties,  that  they  are  associated  into  one  order  or 
family  group  (the  Oak  family)  ;  while  the  Birches  and  the  Alders 
form  another  order  not  very  different  in  character,  and  the  Walnuts 
and  Hickories  another.  So  the  Pines,  Firs  or  Spruces,  Larches, 
Cedars,  &c,  obviously  related  among  themselves  so  much  more  than 
they  are  to  any  other  genera,  are  members  of  the  Pine  family ;  the 
Raspberry,  Blackberry,  and  Strawberry,  Avith  many  others,  are  as- 
sociated with  the  Pose  in  the  Pose  family ;  and  so  on. 

701.  Classes  are  to  orders  what  these  are  to  genera.  They  ex- 
press more  extensive,  or  the  most  extensive  relations  of  species,  each 
class  embracing  all  those  species  which  are  framed  upon  the  same 
general  plan  of  structure,  however  differently  that  plan  may  be 
carried  out  in  particulars.  Thus  all  Exogenous  or  Dicotyledonous 
plants  constitute  one  class,  their  stems,  their  embryo,  their  leaves, 
&c.  being  constructed  upon  the  same  general  plan  in  all  the  species, 
while  Endogenous  or  Moncotyledonous  plants  for  the  same  reasons 
compose  another  class. 

702.  The  sequence  of  groups,  rising  from  particular  to  universal, 
is  Species,  Genus,  Order,  Class  ;  or,  in  descending  from  the  univer- 
sal to  the  particular, 

Class, 

Order, 

Genus, 

Species. 

703.  These  are  the  common  framework  of  all  methods  of  classifi- 
cation, both  in  the  animal  and  the  vegetable  kingdoms.  But  these 
do  not  exhaust  our  powers  of  analysis,  nor  express  all  the  gradations 
which  we  may  observe  in  the  relationship  of  species.  They  merely 
gather  up  what  are  deemed  the  most  essential  indications  of  re- 
lationship, and  express  them  under  three  grades  superior  to  species, 
which  always  carry  with  them  distinctive  names.  But  a  more  elab- 
orate analysis  is  often  requisite,  on  account  of  the  large  number 
of  objects  to  be  arranged,  and  the  various  degrees  of  relationship 
which  may  come  into  view.  And  these,  when  needful,  are  expressed 
in  a  series  of  intermediate  groups  or  divisions,  which  may  or  may 
not  require   distinctive  names.     Karnes  for  them  are,  however,  a 


ORDERS,    CLASSES,   AND    THEIR    SUBDIVISIONS.  361 

great  convenience,  especially  for  those  which  are  most  natural  and 
definite.  For  some  of  these  intermediate  groups  may  be  as  dis- 
tinctly marked  as  are  those  which  we  call  genera  or  orders. 

704.  The  great  advantages  and  proper  use  of  this  intermediate 
grouping  are,  that  it  secures  all  the  benefits  of  complete  analysis 
without  undue  multiplication  of  genera  and  orders,  and  that,  by  ex- 
tending the  scale,  more  grades  of  relationship  may  be  noted,  and  the 
Avhole  expressed  in  our  systems  in  truer  perspective.  Accordingly, 
when  groups  of  species  below  what  we  take  for  genera  are  recog- 
nized, and  found  to  be  so  well  marked  that  by  a  little  lowering  of 
the  scale  they  would  be  received  as  genera,  they  are  denominated 
Subgenera.  If  less  definite,  Ave  term  them  merely  Sections.  For 
example,  Pyrus,  the  Pear  genus,  embraces  Apples,  Pears,  Crab- 
apples  and  the  like ;  and  the  Pear  itself  is  the  type  or  normal  rep- 
resentative. From  this  the  Apple  and  the  several  species  of  Crab- 
apple  differ  considerably,  but  not  quite  enough  to  warrant  generic 
separation:  they  are  therefore  recognized  as  forming  a  subgenus, 
Mains,  of  the  genus  Pyrus.  Again,  the  Bramble  genus,  Rubus,  com- 
prises both  Raspberries  and  Blackberries,  which,  although  distin- 
guished by  everybody,  are  not  so  much  or  so  definitely  different  from 
each  other  as  Apples  and  Crab-apples  are  from  Pears ;  so  they  are 
ranked  merely  as  sections  of  the  Bramble  genus.  If  we  were  to 
receive  all  such  particular  groups  of  species  as  genera,  and  give  them 
substantive  names,  as  many  naturalists  are  doing,  the  nicer  grada- 
tions of  affinity  would  be  disregarded,  while  genera  would  be  reck- 
oned by  tens  of  thousands  ;  at  length  half  our  species  would  become 
genera  with  substantive  names,  and  the  whole  advantage  of  classifi- 
cation and  nomenclature  would  be  lost.  The  proper  discrimination 
of  genera  is  the  real  test  of  a  naturalist. 

705.  When  groups  intermediate  between  genera  and  orders  are 
admitted,  they  are  generally  denominated  Tribes,  and  their  divis- 
ions, if  any,  Subtribes.  But  the  highest  divisions  of  orders,  when 
marked  by  characters  of  such  importance  that  it  might  fairly  be 
questioned  whether  they  ought  not  to  be  received  as  independent 
orders,  take  the  name  of  Suborders.  For  example,  the  great 
Rose  family,  as  Ave  receiATe  it,  embraces  three  suborders ;  one  of 
them  represented  by  the  Plum,  Peach,  Almond,  &c. ;  a  second,  by 
the  Pear,  Quince,  HaAvthorn,  and  the  like ;  and  the  third,  by  the 
Rose  itself  and  its  immediate  relatives.  Some  botanists  receive 
these  three  as  so  many  orders :  Ave  regard  them  as  suborders,  be- 

31 


362  PRINCIPLES    OF   CLASSIFICATION. 

cause  of  the  strong  family  likeness  which  pervades  the  whole,  and 
of  the  transitions  between  them.  In  the  larger  of  these  suborders, 
or  the  proper  Rose  family,  we  recognize  three  tribes :  one  repre- 
sented  by  the  Rose  genus  itself;  one  by  the  Bramble  genus,  with 
the  Strawberry,  Cinquefoil,  Avens,  &c. ;  and  the  third  by  Spiraea 
and  its  near  relations.  And,  again,  the  second  and  larger  of  these 
embraces  genera  winch  are  different  enough  to  be  ranked  under 
several  subtribes. 

706.  Upon  the  same  principles,  groups  may  be  interposed  between 
the  orders  and  the  classes,  of  which  the  highest  kind  will  take  the 
name  of  Subclasses.  And  even  above  classes  we  have  the  most 
comprehensive  division  of  all  plants  into  a  higher  and  a  lower  grade 
or  Series  (98)  ;  which  brings  us  up  to  the  vegetable  Kingdom, 
one  of  the  three  great  departments  of  Nature. 

707.  To  exhibit  the  whole  sequence  or  stages  of  natural-history 
classification,  so«that  the  student  may  see  the  relative  rank  of  groups, 
designated  by  the  terms  which  have  now  been  explained,  they  are 
here  presented,  arranged  in  a  descending  series,  beginning  with  the 
primary  division  of  natural  objects  into  kingdoms,  and  indicating  by 
small  capitals  those  of  fundamental  importance  and  universal  use  in 
classification. 

Kingdoms, 
Series, 

Classes, 

Subclasses, 

Orders  or  Families, 
Suborders, 
Tribes, 

Subtribes, 
Genera, 

Subgenera, 
Species, 

Varieties, 

Individuals. 

708.  Characters.  An  enumeration  of  the  distinguishing  marks,  or 
points  of  difference  between  one  class  or  order,  &c.  and  the  others, 
is  termed  its  character.  Characters  accordingly  properly  embrace 
only  those  points  which  are  common  to  all  plants  of  the  group,  but 
not  to  the  other  groups  of  the  same  rank.  The  characters  of 
classes,  &c.  are  restricted  to  those  general  peculiarities  of  structure 
upon  which  these  great  groups  are  established :  the  ordinal  charac- 
ter recites  the  particulars  in  which  the  plants  it  comprises  differ 


CHARACTERS. BINOMIAL    NOMENCLATURE.  363 

from  all  others  of  the  class  ;  the  generic  character  enumerates 
those  points  which  distinguish  the  plants  of  the  genus  in  question 
from  all  others  of  the  same  order  or  suborder ;  the  specific  character 
indicates  the  differences  between  species  of  the  same  genus  ;  —  to 
which  in  botanical  works  more  or  less  of  general  description,  accord- 
ing to  the  plan  and  extent  of  the  work,  is  generally  added. 

709.  A  complete  system  of  Botany  will  therefore  comprise  a 
methodical  distribution  of  plants  according  to  their  organization, 
Avith  their  characters  arranged  in  proper  subordination  ;  so  that  the 
investigation  of  any  one  particular  species  will  bring  to  view,  not 
only  its  name  (which  separately  considered  is  of  little  importance), 
but  also  its  plan  of  structure,  both  in  general  and  in  particular,  its 
relationships,  essential  qualities,  and  whole  natural  history.  The 
classification  and  the  method  of  investigation  in  natural  history  con- 
stitute not  only  the  most  complete  arrangement  known  for  the  col- 
location of  a  vast  amount  of  facts,  but  also  the  best  system  of  prac- 
tical logic ;  and  the  study  exercises  and  sharpens  at  once  both  the 
powers  of  reasoning  and  of  observation,  more,  probably,  than  any 
other  pursuit.  As  a  system  for  collocating  facts  for  convenient  ref- 
erence, a  great  practical  advantage  of  natural  history  is  secured  by 
its  happily  devised 

710.  Binomial  Nomenclature.  Since  the  time  of  Linnams,  who  in- 
troduced the  system,  the  scientific  name  of  every  plant  is  expressed 
by  two  words,  viz.  by  the  name  of  its  species  appended  to  that  of 
its  genus,  each  of  a  single  word.  That  of  the  genus,  i.  e.  the  ge- 
neric name,  is  a  substantive ;  that  of  the  species,  or  the  specific 
name,  is  an  adjective  adjunct.  The  same  name  is  never  employed 
for  different  genera ;  the  same  specific  name  is  not  available  for 
more  than  one  species  of  the  same  genus,  but  may  be  used  in  any 
other  genus.  A  few  thousand  names  accordingly  serve  completely 
to  designate  something  like  8,000  genera  and  nearly  100,000  species 
of  plants,  in  a  manner  which  obviates  all  confusion,  and  does  not 
greatly  burden  the  memory.  The  generic  name  of  a  plant  answers 
to  the  surname  of  a  person,  as  Brown  or  Jones  ;  the  specific  name 
answers  to  the  baptismal  name,  as  John  or  James.  Thus,  Quercus 
alba  is  the  botanical  appellation  of  the  White  Oak  ;  Quercus  being 
the  substantive  name  for  the  genus,  and  alba  (white)  the  adjec- 
tive name  for  this  particular  species  ;  while  the  Red  Oak  is  named 
Quercus  rubra  ;  the  Scarlet  Oak,  Quercus  coccinea  ;  the  Live  Oak, 
Quercus  virens ;  the  Bur  Oak,   Quercus  macrocarpa ;  and  so  on. 


364  PRINCIPLES   OP   CLASSIFICATION. 

The  scientific  names  of  plants  are  all  Latin  or  Latinized ;  and  that 
of  the  species  always  follows  that  of  the  genus. 

711.  Generic  names  in  botany  are  derived  from  various  sources. 
Those  of  plants  known  to  the  ancients  generally  preserve  their  clas- 
sical appellations  ;  as,  for  example,  Qicercus,  Fagus,  Corylus,  Prunus, 
Myrtus,  Viola,  &c.  For  plants  since  made  known,  even  their  barba- 
rous names  are  often  adopted,  when  susceptible  of  a  Latin  termina- 
tion, and  not  too  uncouth ;  for  example,  Thcea  and  Coffcea,  for  the 
Tea  and  Coffee  plants,  Patnbusa  for  the  Bamboo,  Yucca,  Negundo, 
&c.  But  more  commonly,  new  generic  names,  when  wanted,  have 
been  framed  by  botanists  to  express  some  botanical  character,  habit, 
or  obvious  peculiarity  of  the  plants  they  designate ;  such  as  Arena- 
ria,  for  a  plant  winch  grows  in  sandy  places ;  Dentaria,  for  a 
plant  with  toothed  roots ;  Lunaria,  for  one  with  moon-like  pods ; 
Sanguinaria,  for  the  Bloodroot  with  its  sanguine  juice  ;  Crassula, 
for  some  plants  with  remarkably  thick  leaves.  These  are  instances 
of  Latin  derivatives ;  but  recourse  is  more  commonly  had  to  the 
Greek  language,  in  which  compounds  of  two  words  are  much  more 
readily  made,  expressive  of  peculiarities  ;  such  as  Menispermum,  or 
Moonseed  ;  Lithospermum,  for  a  plant  with  stony  seeds  ;  Melanthium, 
for  a  genus  whose  flowers  turn  black  or  dusky;  Epidendrum,  for 
certain  Orchideous  plants  which  grow  upon  trees ;  Liriodendron, 
for  a  tree  which  bears  lily-shaped  flowers,  &c.  Genera  are  also 
dedicated  to  distinguished  persons ;  a  practice  commenced  by  the 
ancients  ;  as  Pceonia,  which  bears  the  name  of  Preon,  who  is  said  to 
have  employed  the  plant  in  medicine  ;  and  Euphorbia,  Artemisia,  and 
Asclepias  are  also  examples  of  the  kind.  Modern  names  of  this 
kind  are  freely  given  in  commemoration  of  botanists,  or  of  persons 
who  have  contributed  to  the  advancement  of  natural  history.  Mag- 
nolia, Bignonia,  Lobelia,  and  Lonicera,  dedicated  to  Magnol,  Big- 
non,  Lobel,  and  Lonicer,  are  early  instances ;  Linncea,  Tournefortia, 
Jussicea,  HaUeria,  and  Gronovia,  bear  the  names  of  the  most  cel- 
ebrated botanists  of  the  eighteenth  century ;  and  at  the  present  day 
almost  every  devotee  of  the  science  is  thus  commemorated. 

712.  Specific  names  are  adjuncts,  and  mostly  adjectives,  adopted 
on  similar  principles.  Most  of  them  are  expressive  of  some  char- 
acteristic or  obvious  trait  of  the  species  ;  as,  Magnolia  grandijlora, 
the  Large-flowered  Magnolia ;  M.  macropliylla,  the  Large-leaved 
Magnolia ;  M.  glauca,  which  has  the  foliage  glaucous  or  whitened 
underneath ;  or  Viola  tricolor,  from  the  three-colored  corolla  of  the 


NATURAL    AND    ARTIFICIAL    SYSTEMS.  365 

Pansy  ;  V.  rostrata,  a  remarkably  long-spurred  species ;  V.  rotundi- 
folia,  with  rounded  leaves  ;    V.  lanceolata,  with  lanceolate  leaves  ; 

V.pedata,  with  pedately  parted  leaves  ;  V.  primulcefolia,  where  the 
leaves  are  compared  to  those  of  the  Primrose ;  and  V.  pubescens, 
with  pubescent  or  hairy  herbage.  Sometimes  the  specific  name  re- 
fers to  the  country  which  the  plant  inhabits  or  was  first  found  in,  as 

Viola  Canadensis,  the  Canadian  Violet ;  or  to  the  station  where  it 
naturally  grows,  as  V.  palustris  (Marsh  Violet).  Sometimes  it  com- 
memorates the  discoverer  or  describer,  when  it  rightly  takes  the 
genitive  form,  as  Viola  Muhlenbergii,  V.  Nuttallii,  &c.  When  com- 
memorative names  are  given  merely  in  compliment  to  a  botanist  un- 
connected with  the  discovery  or  history  of  the  plant,  the  adjective  form 
is  preferred ;  as,  Carex  Torreyana,  C  Hookeriana,  &c. :  but  this  rule 
is  not  universally  followed.  Specific  names  are  sometimes  substantive ; 
as,  Magnolia  Umbrella,  Ranunculus  Flammula,  Hypericum  Sarothra, 
Linaria  Cymbalaria,  &c.  (most  of  these  being  old  generic  names 
used  as  specific) ;  when  they  do  not  necessarily  accord  with  the 
genus  in  gender.  These,  as  well  as  all  specific  names  taken  from 
persons  or  countries,  are  to  be  written  with  a  capital  initial  letter. 

713.  Varieties  may  be  designated  by  names  when  they  are  re- 
markable enough  to  require  it.  The  name  of  the  variety,  when 
used  at  all,  follows  that  of  the  species,  and  is  formed  on  the  same 
plan.  Subgenera  need  to  be  designated  by  names,  which  are  sub- 
stantive, and  on  the  same  principle  as  generic  names.  These  are 
convenient  to  refer  to,  but  are  not  a  part  of  the  proper  name  of 
a  plant,  which  is  that  of  the  genus  and  species  only. 

714.  The  names  of  genera  and  species  are  the  same  in  all  botani- 
cal systems,  and  therefore  are  properly  alluded  to  here.  But  those 
of  orders,  and  all  other  groups  higher  than  genera,  vary  in  plan 
with  the  system  adopted.     Classifications  are  of  two  sorts,  viz. 

715.  Natural  and  Artificial  Systems.    A  natural  system  carries  out 

in  practice  as  perfectly  as  possible  the  principles  sketched  in  this 
chapter,  arranging  all  known  species  in  groups  of  various  grades  in 
view  of  their  whole  plan  of  structure,  so  placing  each  genus,  tribe, 
order,  &c.  next  to  those  it  most  resembles  in  all  respects.  An  arti- 
ficial system  arranges  the  genera  by  some  one  character,  or  set  of 
characters,  chosen  for  convenience,  disregarding  other  considerations. 
It  aims  only  to  provide  an  easy  mode  of  ascertaining  the  names  of 
plants,  and  does  not  attempt  to  express  their  points  of  resemblance 
generally,  but  serves  nearly  the  same  purpose  as  a  dictionary. 
31* 


366  THE    PRINCIPLES    OF 

716.  Artificial  systems  are  no  longer  used  in  botany,  except  as 
keys  or  helps  in  referring  plants  to  their  proper  groups  in  natural 
arrangements.  But  the  celebrated  Artificial  System  of  Linnaeus 
so  long  prevailed,  and  has  exerted  so  great  an  influence  over  the 
progress  of  the  science,  that  it  is  still  desirable  for  the  student  to 
understand  it.  It  will  therefore  be  explained,  after  we  have  illus- 
trated the  principles  of  the  Natural  System  of  Botany. 


CHAPTER     II. 

OF  THE  NATURAL  SYSTEM  OF  BOTANY. 

717.  The  object  proposed  by  the  Natural  System  of  Botany  is 
to  bi'ing  together  into  groups  those  plants  which  most  nearly  resem- 
ble each  other,  not  in  a  single  and  perhaps  relatively  unimportant 
point  (as  in  an  artificial  classification),  but  in  all  essential  particu- 
lars ;  and  to  combine  the  subordinate  groups  into  successively  more 
comprehensive  natural  assemblages,  so  as  to  embrace  the  whole 
vegetable  kingdom  in  a  methodical  arrangement.  All  the  charac- 
ters which  plants  present,  that  is,  all  their  points  of  agreement  or 
difference,  are  employed  in  the  classification ;  those  which  are  com- 
mon to  the  greatest  number  of  plants  being  used  for  the  primary 
grand  divisions ;  those  less  comprehensive,  for  subordinate  groups, 
&c. ;  so  that  the  character,  or  description  of  each  group,  when  fully 
given,  actually  expresses  the  main  particulars  in  which  the  plants  it 
embraces  agree  among  themselves,  and  differ  from  other  groups  of 
the  same  rank.  This  complete  analysis  being  carried  through  the 
system,  from  the  primary  divisions  down  to  the  species,  it  is  evident 
that  the  study  of  a  single  plant  of  each  group  Avill  give  a  correct 
general  idea  of  the  structure,  habits,  and  even  the  sensible  proper- 
ties, of  the  whole. 

718.  For  it  is  evident  that  the  relationships  of  plants  are  real; 
that  there  is  not  only  a  general  plan  of  vegetation  (with  which  the 
student  has  already  become  familiar),  but  also  a  plan  in  the  relations 
which  subsist  between  one  plant  and  another ;  that  the  species  sustain 
to  each  other  the  relation  of  parts  to  a  whole,  —  so  that  this  whole, 
or  vegetable  kingdom,  is  an  organized  system.     And  this  system,  as 


THE   NATURAL    SYSTEM   OF    CLASSIFICATION.  367 

far  as  comprehended,  may  be  to  a  good  degree  expressed  in  our 
classification.  This  idea  of  plan  and  system  in  nature  supposes  a 
Planner,  or  a  mind  which  has  ordered  things  so,  with  intelligence  and 
purpose  •,  and  it  is  this  plan,  or  its  evidences  and  results,  which  the 
naturalist  is  endeavoring  to  investigate.  The  botanist,  accordingly, 
does  not  undertake  to  contrive  a  system,  but  he  strives  to  express  in 
a  classification,  as  well  as  he  can,  the  System  of  Nature,  or,  in  other 
words,  the  Plan  of  the  Creator  in  the  Vegetable  Kingdom. 

719.  "  So  there  can  be  only  one  natural  system  of  botany,  if  by 
the  term  we  mean  the  plan  according  to  which  the  vegetable  crea- 
tion was  called  into  being,  with  all  its  grades  and  diversities  among 
the  species,  as  well  of  past  as  of  the  present  time.  But  there  may 
be  many  natural  systems,  if  Ave  mean  the  attempts  of  men  to  inter- 
pret and  express  the  plan  of  the  vegetable  creation,  —  systems 
which  Avill  vary  with  our  advancing  knowledge,  and  with  the  judg- 
ment and  skill  of  different  botanists,  —  and  which  must  all  be  very 
imperfect.  They  will  all  bear  the  impress  of  individual  minds,  and 
be  shaped  by  the  current  philosophy  of  the  age.  But  the  endeavor 
always  is  to  make  the  classification  a  reflection  of  Nature,  as  far  as 
any  system  can  be  which  has  to  express  such  a  vast  and  ever  in- 
creasing array  of  facts,  and  most  various  and  intricate  relations,  in 
a  series  of  definite  propositions,  and  have  its  divisions  and  subdi- 
visions following  each  other  in  some  fixed  order."  Our  so-called 
natural  methods  must  always  fail  to  give  more  than  an  imperfect 
and  considerably  distorted  reflection,  not  merely  of  the  plan  of  the 
vegetable  kingdom,  but  even  of  our  knowledge  of  it ;  and  every 
form  of  it  yet  devised,  or  likely  to  be,  is  more  or  less  artificial,  in 
some  of  its  parts  or  details.     This  is  inevitable,  because,  — 

720.  (1st.)  The  relationships  of  any  group  cannot  always  be  right- 
ly estimated  before  all  its  members  are  known,  and  their  whole 
structure  understood ;  so  that  the  views  of  botanists  are  liable  to  be 
modified  with  the  discoveries  of  every  year.  The  discovery  of  a 
single  plant,  or  of  a  point  of  structure  before  misunderstood,  has 
sometimes  changed  materially  the  position  of  a  considerable  group 
in  the  system,  and  minor  alterations  are  continually  made  by  our  in- 
creasing knowledge.  (2d.)  The  groups  which  we  recognize,  and  dis- 
tinguish as  genera,  tribes,  orders,  &c,  are  not  always,  and  perhaps 
not  generally,  completely  circumscribed  in  nature,  as  we  are  obliged 
to  assume  them  to  be  in  our  classification.  This  might  be  expected 
from  the  nature  of  the  case.     For  the  naturalist's  groups,  of  what- 


3G8  THE    PRINCIPLES    OP 

ever  grade,  are  not  realities,  but  ideas  ;  their  consideration  involves 
questions,  not  of  things,  between  which  absolute  distinctions  might 
be  drawn,  but  of  degrees  of  resemblance,  which  may  be  expected  to 
present  infinite  gradations.  (3d.)  Although  the  grades  of  affinity 
among  species  are  most  various,  if  not  wholly  indefinite,  the  nat- 
uralist reduces  them  all  to  a  few,  and  treats  his  genera,  tribes,  &c. 
as  equal  units,  or  as  distinguished  by  characters  of  about  equal  value 
throughout,  —  which  is  far  from  being  the  case.  (4th.)  The  nat- 
uralist in  his  works  is  obliged  to  arrange  the  groups  he  recognizes  in 
a  lineal  series  ;  but  each  genus,  or  order,  &c.  is  very  often  about 
equally  related  to  three  or  four  others  ;  so  that  only  a  part  of  the 
relationship  of  plants  can  practically  be  indicated  in  the  published 
arrangement. 

721.  The  natural  system  as  sketched  by  Bernard  and  A.  L.  Jus- 
sieu,  and  improved  by  the  labors  of  succeeding  botanists,  essentially 
consists  of  an  arrangement  of  the  known  genera  according  to  their  af- 
finities under  two  hundred  or  more  natural  orders,  and  of  these  under 
a  few  great  types  or  classes.  What  is  now  most  wanted  to  complete 
the  system  is  a  truly  natural  arrangement  of  the  orders  under  the 
great  classes,  like  that  of  the  genera  under  their  respective  orders. 
Until  this  is  done,  the  series  in  which  the  orders  follow  one  another 
in  botanical  works  must  not  be  regarded  as  a  part  of  the  system  of 
nature.  Different  authors  adopt  different  modes  of  arranging  them ; 
and  all  of  them  that  a  learner  could  use  are  avowedly  more  or  less 
artificial. 

722.  Omitting  all  historical  details  and  statements  of  more  or  less 
conflicting  views,  we  will  briefly  sketch  the  outlines  of  the  principal 
divisions  of  the  vegetable  kingdom,  according  to  the  natural  system 
as  we  now  practically  receive  it.  In  explaining  the  principles  of 
classification,  we  proceeded  from  the  individual  to  the  class.  In  ex- 
amining the  actual  construction  of  the  system  of  botany,  it  is  simpler 
to  regard  the  vegetable  kingdom  as  a  Avhole,  and  show  how  it  is  nat- 
urally divided  and  subdivided.  This  is  the  course  a  student  must 
follow  with  an  unknown  plant  before  him,  which  he  wishes  to  refer 
first  to  its  class,  then  to  its  order,  and  finally  to  its  genus  and 
species. 

723.  The  long  and  complex  series,  stretching  from  the  highest 
organized  vegetable  down  to  the  simplest  and  minutest  of  the  Fungi 
and  Algre,  is  most  naturally  divided,  as  we  have  already  seen,  into 
two  parts,  forming  a  higher  and  a  lower  grade  or  series  (98),  viz. 


THE    NATURAL    SYSTEM    OF    CLASSIFICATION.  369 

Scries  I.  Pelenogamous  (or  Phanerogamous)  or  Flower- 
ing Plants  (114,  117),  which  produce  flowers  and  seeds,  the  latter 
containing  a  ready-formed  embryo. 

Series  II.  Cryptogamous  or  Flowerless  Plants  (113, 
117,  651),  whose  organs  of  reproduction  are  not  flowers,  but  some 
more  or  less  analogous  apparatus,  and  which  are  propagated  by 
spores  or  specialized  cells. 

724.  "We  have  next  to  consider  how  these  two  series  may  be 
themselves  divided,  in  view  of  the  most  general  and  important  points 
of  difference  which  the  plants  they  comprise  exhibit.  Whenever 
Phamogamous  plants  rise  to  arborescent  forms,  a  difference  in  port 
and  aspect  at  once  ax-rests  attention ;  that  which  distinguishes  our 
common  trees  and  shrubs  from  Palms  and  the  like  (Fig.  184).  On 
examination,  this  is  found  to  accompany  a  well-marked  important 
difference  in  the  structure  of  the  stem  or  wood,  and  in  its  mode  of 
growth.  The  former  present  the  exogenous,  the  latter  the  endoge- 
nous structure  or  growth  (200-203,  207,  &c.).  This  difference  is 
equally  discernible,  if  not  so  striking,  in  the  annual  or  herbaceous 
stems  of  these  two  sorts  of  Phamoganious  plants.  A  difference  is 
also  apparent  in  their  foliage  ;  the  former  generally  have  reticulat- 
ed, or  netted-veined,  the  latter  parallel-veined  leaves  (276).  The 
leaves  of  the  former  usually  fall  off  by  an  articulation ;  those  of  the 
latter  decay  on  the  stem  (309,  310).  The  Phamogamous  series, 
therefore,  divides  into  two  great  classes,  namely,  into  Exogenous 
and  Endogenous  plants,  more  briefly  named  Exogens  and  Endo- 
gens.  The  difference  between  the  two  not  only  pervades  their 
whole  port  and  aspect,  but  is  manifest  from  the  earliest  stage,  in  the 
plan  of  the  embryo.  The  embryo  of  Exogens,  as  already  shown,  is 
provided  with  a  pair  of  cotyledons  (or  sometimes  with  more  than 
one  pair)  ;  that  of  Endogens,  with  only  one  ;  whence  the  former  are 
also  termed  Dicotyledonous,  and  the  latter  Monocotyledo- 
nous  plants  (128,  641-643):  names  introduced  by  Jussieu,  the 
father  of  this  branch  of  botany.*  Taking  these  divisions  for  classes, 
Ave  have 

*  There  is,  perhaps,  no  real  and  complete  exception  to  the  coincidence  of  an 
exogenous  stem  with  a  dicotyledonous  (or  polycotyledonous)  embryo,  and  of  an 
endogenous  stem  with  a  monocotyledonous  embryo.  Nyctaginaceous  plants 
and  some  others  have  a  few  vascular  bundles  scattered  through  their  pith,  but 
the  rest  of  the  wood  is  regularly  exogenous.  The  stalk  of  Podophyllum  imi- 
tates an  Endogen,  but  the  subterranean  rootstock  is  truly  exogenous,  as  it  should 


370  THE   PRINCIPLES    OF 

Class  I.  Exogenous  or  Dicotyledonous  Plants  ;  those 
with  endogenous  stems,  netted-veinecl  leaves,  and  dicotyledonous  (or 
rarely  polycotyledonous)  embryo ; 

Class  II.  Endogenous  or  Monocotyledonous  Plants  ; 
those  with  endogenous  stems,  mostly  parallel-veined  leaves,  and 
monocotyledonous  embryo. 

725.  Without  entering  here  into  a  particular  explanation  of  the 
diversities  of  structure  which  Cryptogamous  plants  present,  suffice 
it  to  say  that  they  exhibit  three  grades  of  simplification  as  to  their 
vegetation,  which  appear  to  correspond  with  three  different  modes 
of  fertilization.  Plants  of  the  highest  grades  of  the  Cryptogamous 
series  have  wood  and  ducts  in  their  composition  (i.  e.  they  are  vascu- 
lar plants,  111),  and  display  the  ordinary  type  of  vegetation,  viz. 
with  an  axis  or  stem,  bearing  distinct  foliage.  But  this  stem  in 
structure  is  neither  endogenous  nor  exogenous,  and  grows  from  the 
apex  only,  having  no  primary  root ;  whence  these  vascular  Flower- 
less  plants  have  been  called  Acrogens,  or  Acrogenous  plants. 
Of  this  kind  are  Ferns,  Lycopodiacea?,  Equisetaceoe  or  Horsetails, 
&c.  These  plants,  it  appears,  produce  their  organs  analogous  to 
flowers,  and  have  their  fecundation  effected,  once  for  all,  upon  the 
infantile  or  germinating  plantlet,  and  the  result  is  the  origination  of 
a  bud,  which  develops  into  the  adult  plant ;  and  that  bears  the  fruit, 
in  the  form  of  spore-cases  and  spores  (6G3).  Here  then  are  the 
characters  of 

Class  III.  Acrogenous  Plants  ;  Cryptogamous  plants,  with 
a  distinct  axis  and  mostly  with  foliage,  having  wood  and  ducts  in 
their  composition :  fertilization  occurring  upon  a  transient  germinat- 
ing plantlet,  and  giving  rise  to  the  adult  plant. 

726.  The  other  Cryptogamous  plants,  being  composed  of  paren- 
chyma only,  (or  with  slight  exceptions,)  are'  called  Cellular  plants 
(111).  Among  them  the  Mosses  and  Liverworts  present  for  the 
most  part  the  ordinary  plan  of  vegetation ;  their  organs  analogous 
to  flowers  appear  in  the  adult  plant ;  and  the  fertilization  of  the 
pistillidium  gives  origin  to  a  sporangium  in  which  a  multitude  of 
spores,  capable  of  germination,  are  developed.     These  compose 

Class  IV.  Anophytes  :  cellular  Cryptogamous  plants,  with 
distinct  stem  and  foliage,  or  sometimes  these  parts  confluent  into  a 

be.      The  trunks  or  rootstocks  of  Water-Lilies  appear  to  be  endogenous ;  but 
those  who  have  investigated  them  minutely,  declare  that  they  are  not  really  so. 


THE   NATURAL   SYSTEM   OF    CLASSIFICATION.  371 

frond,  composed  of  parenchyma  alone  :  fertilization  giving  rise  to  a 
sporangium  filled  with  spores. 

727.  The  remaining  and  lower  grade  consists  of  plants  such  as 
Lichens,  Seaweeds  or  Alga},  and  Fungi,  which  exhibit  no  clear  dis- 
tinction into  stem,  root,  and  leaves,  but  consist  of  single  cells  or  rows 
of  cells  in  their  loAvest  grades,  and  in  the  higher,  of  masses  of  cells 
disposed  in  almost  every  shape,  but  tending  mostly  to  flat  strata  or 
expansions ;  hence  the  vegetation  is  termed  a  thallus  (or  bed),  and 
this  word  gives  a  name  to  the  class,  viz. 

Class  V.  Thallophytes  :  cellular  Cryptogamous  plants  with 
no  distinction  of  axis  and  foliage  ;  their  spores  mostly  directly  fer- 
tilized (as  explained  in  another  place,  656-661). 

728.  These  five  classes  are  unequal  in  extent  and  diversity ;  the 
Exogenous  class  containing  much  the  largest  number  of  orders  ;  the 
Endogens  also  comprising  a  considerable  number ;  the  others  com- 
prise few  orders  or  main  types,  but  are  most  of  them  very  rich 
in  tribes,  genera,  and  species. 

729.  Only  the  first  or  highest  class  presents  such  marked  diver- 
sity of  type  among  the  plants  it  comprises  as  to  call  for  the  estab- 
lishment of  subclasses,  that  is,  of  groups  of  such  importance  as  to 
raise  the  question  whether  they  should  not  be  regarded  as  classes. 
This  question  is  raised  by  the  peculiarities  of  Coniferre  (Pines,  Cy- 
presses, the  Yew,  &c),  and  by  the  tropical  order  of  Cycadaceae ;  in 
which,  not  only  are  the  flowers  reduced  to  the  greatest  simplicity, 
but  the  fertile  ones  consist  of  naked  ovules  merely,  borne  on  the 
margins  or  surface  of  a  sort  of  open  leaf,  or  else  of  an  ovule,  without 
anything  answering  to  a  pistil  at  all.  But  as  these  plants  are  truly 
exogenous  and  dicotyledonous  (or  often  polycotyledonous),  the  better 
opinion  is  that  they  should  be  ranked  under  the  Exogenous  or 
Dicotyledonous  class,  as  a  subclass.  So  that,  while  the  main  body 
of  the  first  class  consists  of 

Subclass  I.  Angiospermous  Exogens  :  viz.  those  with 
proper  pistils  enclosing  their  ovules  in  an  ovary,  in  the  ordinary 
manner ;  the  pollen  to  fertilize  the  ovules  received  upon  a  stigma 
(420,  559,  574),  — the  others  form  the 

Subclass  II.  Gymnospermous  Exogens  :  those  with  naked 
ovules  and  seeds  (as  the  name  denotes),  which  are  fertilized  by 
direct  application  of  the  pollen  (560,  573,  625). 

730.  The  general  plan  of  the  classes  and  subclasses  may  be  pre- 
sented in  one  view,  as  in  the  subjoined  synopsis. 


372 


THE    NATURAL    CLASSES. 


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ILLUSTRATIONS    OF    THE   NATURAL    ORDERS.  373 

731.  The  arrangement  and  general  character  of  the  principal 
orders  under  each  class  form  the  subject  of  the  ensuing  chapter. 
Before  entering  upon  it,  the 

732.  Nomenclature  of  Orders,  Tribes,  &C.  requires  some  explanation. 
The  names  of  such  groups  are  in  the  plural  number.  As  a  gen- 
eral rule,  the  name  of  an  order  is  that  of  some  leading  or  well-known 
genus  in  it,  prolonged  into  the  adjective  termination  acecB.  Thus, 
the  plants  of  the  order  Avhich  comprises  the  Mallow  {Malva)  are 
called  Malvaceae  ;  that  is,  Plantae  Malvaceae,  or,  in  English,  Malva- 
ceous  plants :  those  of  which  the  Rose  {Rosa)  is  the  well-known 
representative  are  Rosaceae,  or  Rosaceous  plants,  &c.  Some  few 
ordinal  names,  however,  are  differently  formed,  and  directly  indicate 
a  characteristic  feature  of  the  group  ;  as,  for  instance,  Leguminosce, 
or  the  Leguminous  plants,  such  as  the  Pea,  Bean,  &c,  whose  fruit 
is  a  legume  (610)  ;  Umbelliferae,  or  Umbelliferous  plants,  so  named 
from  having  the  flowers  in  umbels  ;  Composite,  an  order  having 
what  were  termed  compound  flowers  by  the  earlier  botanists  (394)  ; 
Labiate,  so  called  from  the  labiate  or  two-lipped  corolla  which 
nearly  all  the  species  exhibit ;  Cruciferae,  which  have  their  four 
petals  disposed  somewhat  in  the  form  of  a  cross  (Fig.  405). 

733.  Suborders,  tribes,  and  all  other  groups  between  orders  and 
genera,  bear  names  framed  upon  the  same  principles,  that  is,  they 
are  plural,  substantively-taken  adjectives,  derived  from  the  name  of 
some  characteristic  genus  of  the  group.  Thus  the  genus  Rosa 
gives  name  to  a  particular  tribe,  Roseae,  of  the  order  Rosaceae  ;  the 
genus  Malva  to  the  tribe  Malveae,  of  the  order  Malvaceae,  &c,  —  the 
termination  in  aceae  being  avoided,  because  reserved  for  ordinal 


CHAPTER     III. 

ILLUSTRATIONS   OF   THE   NATURAL   ORDERS   OR   FAMILIES. 

734.  Some  authors  (such  as  Jussieu  and  Endlicher)  commence 

with  the  lower  extremity  of  the  series,  and  end  with  the  higher ; 

while  others  (as  De  Candolle)  pursue  the  opposite  course,  beginning 

with  the  more  perfect  Flowering  plants,  and  concluding  with  the 

32 


374  ILLUSTRATIONS    OF   THE   NATURAL    ORDERS. 

lowest  grade  of  Flowerless  plants.  The  first  mode  possesses  the 
theoretical  advantage  of  ascending  by  successive  steps  from  the 
simplest  to  the  most  complex  structure  ;  the  second,  the  great  prac- 
tical advantage  of  beginning  with  the  most  complete  and  best  under- 
stood, and  proceeding  gradually  to  the  most  reduced  and  least 
known  forms,  or,  in  other  words,  from  the  easiest  to  the  most  dif- 
ficult ;  and  is  therefore  the  best  plan  for  the  student. 

735.  Until  the  orders  shall  have  been  successfully  associated  into 
natural  alliances  or  superior  groups,  (of  whatever  name,)  it  is  most 
convenient  to  follow  De  Candolle's  arrangement  of  them,  in  a  gen- 
eral way,  with  such  minor  alterations  as  may  be  called  for.  The 
principal  Floras  now  in  use  are  arranged  upon  this  general  method. 
It  commences  with  the  Exogenous  class,  with  those  orders  of  it 
which  are  generally  provided  with  complete  flowers,  and  which  ex- 
hibit the  floral  organs  in  the  most  normal  condition,  according  to 
our  theory  of  the  blossom  (Chap.  IX.,  Sect.  I.  -  III.),  that  is, 
which  have  most  of  the  several  parts  free  and  separate.  It  pro- 
ceeds to  those  which  are  characterized  by  the  union  or  consolida- 
tion of  their  floral  organs,  and  then  to  those  which  are  reduced  or 
simplified  by  the  suppression  or  obliteration  of  parts,  ending  with  the 
Gymnospermous  subclass,  the  flowers  of  which  are  extremely  simpli- 
fied. The  Endogenous  class  succeeds,  with  a  somewhat  analogous 
arrangement,  ending  Avith  Grasses ;  and  the  classes  of  the  Cryp- 
togamous  series  follow  in  the  order  of  their  rank. 

736.  The  following  cursory  sketch  takes  in  the  principal  orders, 
freely  omitting,  however,  small  and  obscure  ones,  as  well  as  certain 
well-characterized  groups  which  have  no  interest  to  the  ordinary 
student,  and  no  indigenous,  naturalized,  or  commonly  cultivated  rep- 
resentatives in  the  United  States.  Certain  exotic  orders  are  also 
omitted  from  the  synopsis  of  the  classes  or  large  divisions,  for  greater 
simplicity,  but  are  briefly  mentioned  in  their  proper  place.  Fuller 
accounts  of  the  natural  orders,  and  of  their  systematic  arrangement, 
structure,  properties,  &c,  must  be  sought  in  more  extensive  works, 
such  as  Lindley's  Vegetable  Kingdom,  De  Candolle's  Prodromus,  &c. 
As  applied  to  the  botany  of  this  country,  what  is  essential  is  comprised 
in  the  Manual  of  the  Botany  of  the  Northern  United  States,  by  the 
present  writer,  and  in  similar  Floras.  The  characters  of  the  orders, 
&c.  are  drawn  up  in  ordinary  botanical  language.  For  explanation 
of  the  technical  terms  used,  the  reader  may  consult  the  Glossary  at 
the  end  of  the  volume. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS.  375 

Series  I.     Flowering    or  Pflenogamous  Plants. 

Plants  furnished  with  flowers  (essentially  consisting  of  stamens 
and  pistils),  and  producing  proper  seeds. 

Class  I.    Exogenous  or  Dicotyledonous  Plants. 

Stem  consisting  of  a  distinct  bark  and  pith,  which  are  separated 
by  an  interposed  layer  of  woody  fibre  and  vessels,  forming  wood  in 
all  perennial  stems  :  increase  in  diameter  effected  by  the  annual 
deposition  of  new  layers  between  the  old  wood  and  the  bark,  which 
are  arranged  in  concentric  zones  and  traversed  by  medullary  rays. 
Leaves  commonly  articulated  with  the  stems,  their  veins  branching 
and  reticulated.  Sepals  and  petals,  when  present,  more  commonly 
in  fives  or  fours,  and  very  rarely  in  threes.  Embryo  with  two  (or 
rarely  more)  cotyledons. 

Subclass  1.  Angiospermous  Exogenous  Plants. 
Ovules  produced  in  a  closed  ovary,  and  fertilized  by  the  action  of 
pollen  through  the  medium  of  a  stigma.  Embryo  Avith  a  pair  of  op- 
posite cotyledons.  (For  convenience,  the  very  numerous  orders  of 
this  subclass  are  divided  into  those  with  polypetalous,  monopetalous, 
and  apetalous  flowers.  This  holds  in  a  general  way ;  but  a  good 
many  genera  and  species  of  mainly  polypetalous,  and  some  of  mono- 
petalous orders,  are  apetalous.  The  character  of  the  following  divis- 
ion must  therefore  be  regarded  as  liable  to  exception  in  this  respect. 
For  example,  many  of  the  genera  of  the  first  order  have  apetalous 
flowers.  —  The  earlier  groups  of  this  division  are  mostly  hypogy- 
nous ;  those  that  succeed,  perigynous  ;  the  last  are  epigynous.) 

Division  I.     Polypetalous  Exogenous  Plants. 
Calyx  and  corolla  both  present ;  and  the  petals  distinct. 

Conspectus  of  the  Orders. 

Group  1.     Ovaries  several  or  numerous  (in  a  few  cases  solitary),  distinct,  when 
in  several  rows  sometimes  cohering  in  a  mass,  but  not  united  into  a  com- 
pound pistil.    Petals  and  stamens  hypogynous.     Seeds  albuminous. 
*  Stamens  or  pistils  (one  or  both)  numerous  or  indefinite. 

Herbs  without  stipules.  Ranunculace^e. 

Shrubs  or  trees.     Corolla  imbricated  in  the  bud.  Magnoliace^e. 

Shrubs  or  trees.     Corolla  valvate  in  the  bud.  Anonace^;. 


376  ILLUSTRATIONS    OF   THE   NATURAL    ORDERS. 

*  *  Stamens  few  or  definite,  mostly  before  the  petals.    Pistils  one  or  few. 
Climbing  plants.     Dioecious  or  monoecious.  Menispermace^e. 

Not  climbing.    Flowers  perfect.    Anthers  opening  by  valves.     Berberidace^e. 

Group  2.  Ovaries  several  and  distinct,  or  perfectly  united  into  a  compound 
pistil  of  several  cells.  Embryo  enclosed  in  a  sac  at  the  end  of  the  albu- 
men, or,  in  Nelumbium,  without  albumen.    Aquatic  herbs. 

Carpels  distinct,  immersed  in  a  dilated  top-shaped  torus.  Nelumbiace^:. 

Carpels  united  into  a  several-celled  and  many-ovuled  ovary.        NyiiPHiEACEiE. 

Carpels  distinct  and  free.     Stamens  6  -  18.  Cabombaceje. 

Group  3.  Ovary  compound,  5-celled,  with  the  placenta?  in  the  axis.  Sta- 
mens hypogynous,  indefinite.  Seeds  numerous,  anatropous,  albuminous, 
with  a  small  embryo.  Marsh  herbs,  with  singular  pitcher-shaped  or 
tubular  leaves.  Sarraceniace^e. 

Group  4.     Ovary  compound,  with  parietal  placentae.     Petals  and  sepals  2  or  4, 
deciduous.     Stamens  hypogynous.    Flower  unsymmetrical.    Embryo  small, 
in  copious  albumen,  or  coiled  when  there  is  no  albumen. 
Seeds  albuminous  :  embryo  small  or  minute. 

Polyandrous  :  flower  regular.    Juice  milky  or  colored.  Papa ve raceme. 

Diadelphous  or  hexandrous  :  flower  irregular.  Fumariace.^:. 

Seeds  without  albumen  :  styles  and  stigmas  united  into  one. 

Pod  two-celled.     Radicle  folded  on  the  cotyledons.  Crucifer^:. 

Pod  one-celled.     Embryo  rolled  up.  Capparidaceje. 

Seeds  without  albumen  :  styles  or  stigmas  several.  Resedace^e. 

Group  5.     Ovary  compound,  with  parietal  placental.     Floral  envelopes  mostly 

5-merous ;   calyx  persistent.     Stamens  hypogynous.     Seeds  albuminous. 
Anthers  (5)  adnate,  introrse,  connate.     Corolla  irregular.  Violaceje. 

Anthers  extrorse,  or  innate,  distinct.     Corolla  regular. 

Vernation  circulate.     Petals  marcescent.  Droserace^e. 

Vernation  straight.     Petals  usually  caducous.  Cistace;e. 

Group  6.     Ovary  compound,  with  the  placentas  parietal,  or  2  -  5-celled  from 
their  meeting  in  the  axis.     Stamens  hypogynous.     Seeds  with  a  straight 
embryo  and  little  or  no  albumen. 
Sterile  filaments  or  a  lobed  appendage  before  each  petal.  Parnassiace^e. 

Sterile  filaments  none  :  leaves  opposite. 

Stipules  none  :  leaves  dotted.     Stamens  unsymmetrical.  Hypericace^. 

Stipules  present :  leaves  dotless.     Stamens  symmetrical.  Elatinace^e. 

Group  7.  Ovary  compound,  one-celled  with  a  free  central  placenta,  or  2  - 
several-celled  with  the  placenta  in  the  axis.  Calyx  free  or  nearly  so. 
Stamens  hypogynous  or  perigynous.  Embryo  peripheric,  coiled  more  or 
less  around  the  outside  of  mealy  albumen. 

Petals  and  stamens  numerous.    Ovary  many-celled.    Mesembr y anthem ace^e. 
Petals  3  -  5  or  6,  sometimes  wanting. 

Floral  envelopes  symmetrical.     Stamens  10  or  fewer.       Caryophyllace^e. 

Floral  envelopes  unsymmetrical,  or  stamens  many.  Portulacacejj:. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS.  37.7 

Group  8.  Ovary  compound  and  several-celled,  with  the  placentas  in  the  axis  ; 
or  the  numerous  carpels  more  or  less  coherent  with  each  other  or  with  a 
central  axis.  Calyx  free  from  the  ovary,  with  a  valvate  aestivation.  Sta- 
mens mostly  indefinite,  monadelphous,  or  polyadelphous,  inserted  with  the 
petals  into  the  receptacle  or  base  of  the  petals. 

Anthers  1-celled,  reniform.     Stamens  monadelphous.  Malvaceae. 

Anthers  2-celled.     Fertile  stamens  few,  monadelphous.  Byttneriaceje. 

Anthers  2-celled.     Stamens  polyandrous  or  polyadelphous.  Tiliaceje. 

Group  9.  Ovary  compound,  with  two  or  more  cells,  and  the  placenta;  in  the 
axis,  free  from  the  calyx,  which  is  imbricated  in  aestivation.  Stamens  in- 
definite, or  twice  as  many  as  the  petals,  usually  monadelphous,  hypogy- 
nous.  —  Trees  or  shrubs. 

Leaves  simple,  not  dotted.     Stamens  indefinite.  Camelliace^e. 

Leaves  pellucid-punctate,  mostly  compound.  Aurantiace^e. 

Leaves  compound,  dotless.     Stamens  10  or  less,  monadelphous. 

Seeds  single  in  each  cell,  wingless.  Meliace^e. 

Seeds  several  in  each  cell,  winged.  Cedrelace^e. 

Group  10.  Ovary  compound,  or  of  several  carpels  adhering  to  a  central  axis, 
(or  rarely  distinct  in  the  last  two),  free  from  the  calyx,  which  is  mostly  im- 
bricated in  aestivation.  Stamens  as  many  or  twice  as  many  as  the  petals, 
inserted  on  the  receptacle,  often  monadelphous  at  the  base.  Embryo  large. 
Albumen  little  or  none.    Flowers  perfect,  except  in  some  Rutacece. 

*  Flower  irregular  and  unsymmetrieal.     Albumen  none. 
Stamens  united  over  the  pistil.     Ovules  several  in  each  cell.     Balsaminace^s. 
Stamens  distinct.     Ovules  single  in  each  cell.  TROPiEOLACEiE. 

*  *  Flower  regular  and  mostly  symmetrical. 
Leaves  not  punctate  with  transparent  dots. 

Calyx  valvate.     Albumen  none  :  cotyledons  very  thick.        Limnanthace;e. 
Calyx  imbricated  in  aestivation. 
Embryo  conduplicate  :  the  radicle  bent  down  on  the 

convolute  cotyledons.  Geraniaceje. 

Embryo  straight  or  nearly  so. 

Stamens  (fertile)  5.     Leaves  simple,  entire.  Linaceje. 

Stamens  10.     Leaves  opposite,  compound.  Zygophyllace.e. 

Stamens  10.     Leaves  alternate,  mostly  compound. 

Ovules  more  than  one  in  each  cell.  Oxaeidace.i;. 

Ovules  only  one  in  each  cell.  Sijiarubace^k. 

Leaves  punctate  with  transparent  dots.  Rutace^c. 

Group  11.  Ovary  one,  or  several  and  distinct  or  combined  into  one,  with  one 
or  rarely  two  ovules  in  each  cell.  Calyx  free ;  stamens  more  or  less 
perigynous,  as  many  or  twice  as  many  as  the  petals.  Embryo  large : 
albumen  none.  Shrubs  or  trees  with  a  resinous  or  viscid-milky  juice,  and 
mostly  polygamous  or  dioecious  flowers.  Leaves  not  punctate. — Intem- 
perate climates  represented  only  by  Anacardiace.e. 
32* 


378  ILLUSTRATIONS    OF   THE    NATURAL    ORDERS. 

Group  12.  Ovary  compound,  1  -  5-celled,  with  one  or  two  ovules  erect  from 
the  base  of  the  cells.  Calyx  free  or  partly  adherent.  Stamens  as  many  as 
the  petals  or  sepals  and  opposite  the  former.  Seeds  anatropous,  albumi- 
nous. Woody  plants,  with  a  colorless  juice.  Flowers  regular.  Leaves 
alternate. 

Calyx  obscure.     Petals  valvate,  caducous.    Embryo  minute.  Vitaceje. 

Calyx  more  conspicuous  than  the  petals,  valvate.  Rhamnace/e. 

Group  13.  Ovary  compound,  2 -5-celled,  with  only  one  or  two  ovules  in  each 
cell.  Stamens  as  many  as  the  petals  and  alternate  with  them,  perigynous. 
Seeds  furnished  with  an  arillus,  albuminous,  with  a  large  straight  embryo. 
"Woody  plants,  with  regular  flowers  and  simple  leaves.  —  Represented 
mainly  by  Celastrace^e. 

Group  14.  Ovary  compound  and  2-3-celled,  with  one  or  two  (rarely  3  or  4) 
ovules  in  each  cell,  free  from  the  calyx,  which  is  imbricated  in  aestivation. 
Flowers  often  irregular,  and  sometimes  unsymmetrical.  Stamens  definite, 
hypogynous  or  perigynous.  Shrubs,  trees,  or  herbs.  Leaves  opposite  or 
alternate,  not  punctate. 

Stamens  distinct,  inserted  on  a  hypogynous  or  perigynous  disk. 
Embryo  (except  in  Staphylea)  variously  curved  or  coiled,  and 

destitute  of  albumen.  Sapindace^e. 

Stamens  hypogynous,  without  a  disk. 
Stamens  mostly  monadelphous,  10. 

Flowers  regular.    Embryo  curved ;  albumen  none.  Malpighiace^e. 

Stamens  monadelphous  or  diadelphous,  6  or  8.     Flower  irregu- 
lar and  unsymmetrical.     Embryo  straight  in  albumen.         Polygalace;e. 

Group  15.  Ovary  simple  and  solitary,  free  from  the  calyx;  the  fruit  a  pod. 
Flower  5-merous,  the  odd  sepal  anterior.  Corolla  papilionaceous,  irregu- 
lar, or  sometimes  regular.  Stamens  monadelphous,  diadelphous,  or  dis- 
tinct, mostly  perigynous.     Seeds  destitute  of  albumen 

Stamens  hypogynous,  the  anterior  wanting.     Stipules  none.      Krameriace^e. 
Stamens  mostly  perigynous.     Fruit  a  legume.  Leguminos.e. 

Group  16.  Ovaries  one  or  several,  either  simple  and  distinct,  or  combined 
into  a  compound  ovary  with  two  or  more  cells  and  the  placentae  in 
the  axis.  Petals  and  the  distinct  stamens  perigynous.  Seeds  destitute  of 
albumen. 

*  Calyx  free,  although  often  enclosing  the  ovaries  in  its  tube,  except  when  the 

latter  are  united,  when  it  is  adnate  to  the  compound  ovary,  and  the  sta- 
mens are  indefinite. 

Leaves  alternate,  stipulate.     Cotyledons  plane.  Rosaceje. 

Leaves  opposite,  not  stipulate,  nor  pellucid-punctate.  Calycanthace/E. 

Leaves  opposite,  not  stipulate,  pellucid-punctate.  Myrtace.e. 

*  *  Calyx  free  from  the  compound  ovary.     Stamens  definite.        Lythrace^b. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS.  379 

*  *  *  Calyx-tube  adnate  to  the  compound  ovary.     Stamens  definite. 

Anthers  opening  by  a  pore  at  the  apex.  Melastomace^e. 
Anthers  opening  longitudinally. 

Stipules  between  the  petioles.    Leaves  opposite.  Rhizophorace;e. 
Stipules  none.     Calyx  valvate. 

Cotyledons  convolute.     Fruit  indehiscent,  1-celled.  Combretace^e. 

Cotyledons  plane.     Fruit  mostly  2- 4-celled.  Onagrace^e. 

Group  17.  Ovary  compound,  one-celled,  with  parietal  placentas.  Petals  and 
(with  one  exception)  stamens  inserted  on  the  throat  of  the  calyx.  Flowers 
perfect,  except  in  Papayacete. 

*  Calyx  adherent  to  the  ovary. 

Albumen  none  or  very  little.    Petals  and  stamens  indefinite.  Cactace-s:. 

Albumen  very  copious.     Embryo  minute.     Stamens  5.  Grossulaceje. 

Albumen  present.    Embryo  rather  large.     Stamens  indefinite.  Loasace-S. 

*  *  Calyx  free  from  the  ovary. 
Flowers  perfect.     Stamens  5. 

Stamens  distinct  and  perigynous.  Turnerace^;. 

Stamens  monadelphous,  adnate  to  the  gynophore.  Passiflorace^e. 

Flowers  dioecious.     Stamens  10,  on  the  corolla.  Papayace^e. 

Group  18.  Ovary  compound,  one  -  several-celled,  the  placenta?  parietal  (either 
truly  or  falsely  so).  Calyx  adnate.  Corolla  frequently  monopetalous. 
Stamens  mostly  united  either  by  their  filaments  or  anthers.  Flowers 
dioecious  or  monoecious.  Albumen  none.  Succulent  or  tender  vines  with 
tendrils.  Cucurbitace^e. 

Group  19.  Ovaries  two  or  more,  many-ovuled,  distinct,  or  partly,  sometimes 
completely,  united,  when  the  compound  ovary  is  one-celled  with  parietal 
placenta;,  or  2  -  many-celled  with  the  placentae  in  the  axis.  Calyx  either 
free  from  the  ovary  or  more  or  less  adherent  to  it.  Petals  and  stamens 
inserted  on  the  calyx ;  the  latter  mostly  definite.  Seeds  albuminous,  nu- 
merous. 

Pistils  of  the  same  number  as  the  sepals.  Crassulace^e. 

Pistils  fewer  than  the  sepals,  more  or  less  united.  Saxifragace^e. 

Group  20.  Ovary  compound,  2-  (rarely  3-5-)  celled,  with  a  single  ovule  sus- 
pended from  the  apex  of  each  cell.  Stamens  usually  as  many  as  the  pet- 
als or  the  lobes  of  the  adherent  calyx.    Embryo  small,  in  hard  albumen. 

*  Summit  of  the  (often  2-lobed)  ovary  free  from  the  calyx ;  the  petals  and  sta- 

mens inserted  on  the  throat  of  the  calyx.  Hamamelace^:. 

*  *  Calyx-tube  entirely  adherent  to  the  ovary.  Stamens  and  petals  epigynous. 
Fruit  separable  into  two  dry  carpels.  Flowers  umbellate.  Umbellifer^:. 
Fruit  drupaceous,  usually  of  more  than  two  carpels.  Araliace-e. 
Fruit  a  1  -  2-celled  drape.    Flowers  cymose  or  capitate.  Cornace^;. 


380 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


737.  Ord.  RannilCUlaceaB  {Crowfoot  Family).  Herbaceous,  occa- 
sionally climbing  plants,  with  an  acrid  watery  juice,  and  usually 
palmately  or  ternately  lobed 

or  divided  leaves,  without 
stipules.  Calyx  of  three  to 
six,  usually  five,  distinct 
sepals,  deciduous,  except  in 
Paeonia  and  Helleborus. 
Petals  five  to  fifteen,  or 
often  none.  Stamens  indefi- 
nite, distinct.  Ovaries  nu- 
merous, rarely  few  or  soli- 
tary, distinct,  in  fruit  becoming  achenia  (Fig.  566,  567)  or  follicles 
(Fig.  579,  648,  649),  or  in  Aetata  a  berry.  Embryo  minute,  at  the 
base  of  firm  albumen  (Fig.  650,  610).  —  Ex.  Ranunculus,  the  But- 
tercup (Fig.  645),  which  has  regular 
flowers  with  petals.  Clematis  (Vir- 
gin's Bower,  which  is  the  type  of  a 
tribe),  Anemone  (Fig.  411),  Hepatica 
(Liver-leaf),  &c.  have  no  petals,  but 
the  calyx  is  petaloid.  In  these  the  flow- 
ers are  regular.  The  Larkspur  (Fig. 
398)  and  Monkshood  (Fig.  401)  have 
the  flowers  irregular,  and  the  Colum- 
bine (Fig.  646)  has  petals  in  the  form 
of  spurs.  Aetata  (Baneberry)  and 
one  Larkspur  have  a  solitary  ovary : 
in  the  latter  the  petals  are  consoli- 
dated. Zanthorhiza  (Yellow-root)  has 
only  five  or  ten  stamens.  —  The  juice 
of  all  Banunculaceous  plants  is  acrid,  or  even  caustic :  some,  as  the 
Aconite,  are  virulent  narcotico-acrid  poisons. 

738.  Ord.  DilleniaceSB,  consisting  chiefly  of  tropical  and  Australian 
shrubs  and  trees,  probably  includes  Crossosoma  of  Nuttall,  a  singu- 
lar Californian  genus.  The  order  ranks  between  the  preceding 
and  succeeding,  but  is  nearer  the  former,  from  which  it  is  known  by 
its  arillate  seeds. 

FIG.  645.    Vertical  section  of  the  flower  of  a  Buttercup. 

FIG.  646.  Flower  and  part  of  a  leaf  of  Aquilegia  Canadensis  (Wild  Columbine).  647.  A 
detached  petal.  648.  The  five  carpels  of  the  fruit.  649.  A  separate  follicle.  650.  Vertical 
section  of  the  seed,  showing  the  minute  embryo. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS. 


381 


739.  Ord.  MagllOliacefE  (Magnolia  Family).  Trees  or  shrubs; 
with  ample  and  coriaceous,  alternate,  entire  or  lobecl  leaves,  usually 
punctate  with  minute  transparent  dots  :  stipules  membranaceous,  en- 
veloping the  bud,  falling  off  when  the  leaves  expand.  Flowers  soli- 
tary, large  and  showy.  Calyx  of  three  deciduous  sepals,  colored  like 
the  petals ;  the  latter  in  two  or  more  series  of  three.  Stamens  nu- 
merous, with  adnate  anthers.  Carpels  either  several  in  a  single 
row,  or  numerous  and  spicate  on  the  prolonged  receptacle ;  in  the 
latter  case  usually  more  or  less  cohering  Avith  each  other,  and  form- 
ing a  fruit  like  a  cone  or  strobile.  Seeds  mostly  one  or  two  in  each 
carpel,  sometimes  drupaceous  and  suspended,  when  the  carpels  open, 
by  an  extensile  thread,  composed  of  unrolled  spiral  vessels.  Em- 
bryo minute,  at  the  base  of  homogeneous  fleshy  albumen.  There 
are  three  well-marked  suborders,  by  many  ranked  as  orders,  viz. :  — 


740.  Subord.  Magnolieffi  (Magnolia  Family  proper),  characterized 
principally  as  above,  especially  by  the  stipules  and  the  imbricated 
spiked  carpels :  —  represented  by  Magnolia  and  Liriodendron.  The 
bark,  &c.  is  bitter  and  aromatic,  with  some  acridity. 

741.  Subord.  WilltereSB  (Winter 's-Bark  Family)  has  no  stipules, 
and  the  carpels  occupy  only  a  single  verticil.     These  have  more 

FIG.  651.  Magnolia  glauca.  652.  A  stamen,  seen  from  the  inside,  showing  the  two  lobes  of 
the  adnate  anther.  653.  The  carpels  in  fruit,  persistent  on  the  receptacle,  and  opening  by  the 
dorsal  suture  ;  the  seeds  suspended  by  their  extensile  cord  of  spiral  vessels. 


382 


ILLUSTRATIONS    OF   THE   NATURAL    ORDERS. 


pungent  and  purer  aromatic  properties ;  as  in  Micium,  the  Star- Anise, 
the  seeds  and  pods  of  which  furnish  the  aromatic  oil  of  this  name. 

742.  Sllbord.  SchizandreSB  is  monoecious  or  dioecious,  with  the  pis- 
tils spicate  or  capitate  on  a  prolonged  receptacle ;  the  stamens  often 
monadelphous.  Leaves  sometimes  toothed,  destitute  of  stipules. — 
Ex.  Schizandra.     These  are  mucilaginous,  with  little  aroma. 

743.  Ol'd.  HIoilillliacecE  is  a  small  group,  found  in  the  southern 
hemisphere,  with  pungent  ai'omatic  properties,  most  allied  to  the  last 
order  according  to  Dr.  Hooker  (or  to  Calycanthaceos,  according 
to  Tulasne),  but  chiefly  apetalous,  and  with  opposite  leaves. 

744.  Ol'd.  AnonaceEB  {Custard-Apple  Family).  Trees  or  shrubs, 
with  alternate  entire  leaves,  destitute  of  stipules.  Flowers  large, 
but  dull-colored.     Sepals  3.     Petals  6,  in  two  rows,  valvate  in  aesti- 


vation. Stamens  numerous,  in  many  rows,  with  extrorse  anthers. 
Carpels  few,  or  mostly  numerous  and  closely  packed  together,  some- 
times cohering  and  forming  a  fleshy  or  pulpy  mass  in  the  mature 

FIG.  654.  Flowering  branch  of  the  Papaw  (Asimina  triloba)  of  the  natural  size.  655  The 
receptacle,  with  all  but  the  pistils  removed.  656.  A  stamen,  magnified.  657.  A'iew  of  three 
baccate  pods  from  the  same  receptacle  (much  reduced  in  size) ;  one  cut  across,  another  length- 
wise, to  show  the  large  bony  seeds.    658.  Section  of  the  seed,  to  show  the  ruminated  albumen. 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


383 


fruit.  Seeds  one  or  more  in  each  carpel,  with  a  hard  and  brittle 
testa:  embryo  minute,  at  the  base  of  hard,  ruminated  albumen. 
The  four  species  of  our  so-called  Papaw  (Asimina)  are  our  only  rep- 
resentatives of  this  chiefly  tropical  order,  which  furnishes  the  lus- 
cious custard-apples  of  the  East  and  West  Indies,  &c.  Aromatic 
properties,  with  some  acridity  in  the  bark,  &c.,  prevail  in  the  order. 
Monodora  yields  the  calabash-nutmeg. 

745.  Ord.  MjTisticacefC  {Nutmeg  Family),  consisting  of  a  few  tropi- 
cal trees  (which  bear  nutmegs),  differs  from  Anonacea?  in  havin°* 
monoecious  or  dioecious  and  apetalous  flowers,  &c.  The  aril  and  the 
albumen  of  the  seeds  are  fine  aromatics.  The  common  nutmeg  is 
the  seed  of  Myristica  moschata  (a  native  of  the  Moluccas)  deprived 
of  the  testa :  mace  is  the  aril  of  the  same  species.  The  ruminated 
albumen  is  nearly  peculiar  to  this  family  and  the  Anonaceas. 

746.  Ord.  MenispermacetE  {Moonseed  Family).  Climbing  or  twin- 
ing shrubby  plants,  with  alternate  and  simple  palmately-veined  leaves, 
destitute  of  stipules ;  and  small  flowers  in  racemes  or  panicles, 
mostly  dioecious,  the  parts  commonly  in  two  or  more  rows  of  three 
or  four  each.  Calyx  of  three  to  twelve  sepals,  in  one  to  three  rows, 
deciduous.  Petals  as  many  as  the  sepals  or  fewer,  small,  or  some- 
times wanting  in  the  pistillate  flowers.  Stamens  as  many  as  the 
petals,  and  opposite  them,  or  two  to  four  times  as  many :  anthers 


often  four-celled.     Carpels  usually  several,  but  only  one  or  two  of 
them  commonly  fructify,  at  first  straight,  but  during  their  growth 

FIG.  659.  Staminate  flower  of  Menispermum  Canadense.  660.  A  stamen,  with  its  four- 
lobed  anther.  661.  A  pistillate  flower  of  the  same.  662.  A  solitary  fruit.  663.  Two  drupes 
on  the  same  receptacle,  cut  across  ;  one  through  the  pulpy  exocarp  only,  the  other  through 
the  bony  endocarp  and  seed.  664.  A  drupe  divided  vertically  (the  embryo  here  is  turned  the 
wrong  way).     665.  The  seed,  and,  666,  the  coiled  embryo  detached. 


384 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


often  curved  into  a  ring ;  in  fruit  becoming  berries  or  drupes.  Seeds 
solitary,  filling  the  cavity  of  the  bony  endocarp :  embryo  large, 
curved  or  coiled  in  the  thin  fleshy  albumen.  —  Menispermum,  or 
Moonseed  (Fig.  413,  414,  659-666),  Cocculus.  The  roots  are 
bitter  and  tonic  (e.  g.  Colombo  Root  of  the  materia  medica)  ;  but  the 
fruit  is  often  narcotic  and  acrid ;  as,  for  instance,  the  very  poisonous 
Cocculus  Indiciis  of  the  shops,  once  used  for  rendering  malt  liquors 
more  intoxicating,  and  for  stupefying  fishes. 

747.  Ord.  BerberidaceSB  (Barberry  Family).  Herbs  or  shrubs, 
with  a  watery  juice  ;  the  leaves  alternate,  compound  or  divided,  usu- 
ally without  stipules.  Flowers  perfect.  Calyx  of  three  to  nine 
sepals,  imbricated  in  one  to  several  rows,  often  colored.     Petals  as 


many  as  the  sepals  and  in  two  sets,  or  twice  as  many,  often  with  a 
pore,  spur,  or  glandular  appendage  at  the  base.     Stamens  equal  in 


FIG.  668.  A  shoot  of  Berberis  vulgaris,  the  common  Barberry.  669.  A  flowering  branch 
from  the  axil  of  one  of  its  leaves  or  spines,  the  following  year.  670.  An  expanded  flower. 
671.  A  petal,  nectariferous  near  the  base.  672.  A  stamen  ;  the  anther  opening  by  uplifted 
valves.  673.  Cross-section  of  a  young  fruit.  674.  Vertical  section  ;  the  seeds  attached  at  the 
base.  675.  Vertical  section  of  a  seed  enlarged,  showing  the  large  embryo  with  foliaceous 
cotyledons  and  a  taper  radicle,  surrounded  by  albumen.    676.  The  embryo  separate. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS.  385 

number  to  the  petals  and  opposite  them,  or  rarely  more  numerous ; 
anthers  extrorse,  the  cells  commonly  opening  by  an  uplifted  valve 
(Fig.  475,  G72).  Carpel  solitary,  often  gibbous  or  oblique,  forming 
a  one-celled  pod  or  berry  in  fruit.  Seeds  sometimes  with  an  aril : 
embryo  (often  minute)  surrounded  with  a  fleshy  or  horny  albumen. 
—  Ex.  The  Barberry,  the  sharp  spines  of  which  are  transformed 
leaves  ;  the  Mahonias  are  Barberries  with  pinnated  leaves.  Caulo- 
phyllum  thalictroides,  the  Blue  Cohosh,  is  remarkable  for  its  eva- 
nescent jjericarp  (559),  and  the  consequent  naked  seeds,  which 
resemble  drupes  Podophyllum  peltatum  (the  Mandrake)  presents 
an  exception  to  the  ordinal  character,  having  somewhat  numerous 
stamens,  with  anthers  which  do  not  open  by  valves ;  but  the  latter 
anomaly  is  also  found  in  Nandina.  The  order  is  remarkable  for 
this  valvular  dehiscence  of  the  anthers,  and  for  the  situation  of  both 
the  stamens  and  petals  opposite  the  sepals.  But  this  latter  pecu- 
liarity is  easily  explained  away  (4G1).  The  fruit  is  innocent  or 
eatable  ;  the  roots,  and  also  the  herbage,  sometimes  drastic  or  poison- 
ous, as  in  Podophyllum. 

748.  Ol'd.  NelumbiacCiE  {JSfelumbo  Family).  Aquatic  herbs,  with 
large  leaves  and  flowers,  on  long  stalks  arising  from  a  prostrate 
trunk  or  rhizoma,  which  has  a  somewhat  milky  juice :  the  leaves 
orbicular  and  centrally  peltate.  Calyx  of  four  or  five  sepals,  decid- 
uous. Petals  numerous,  inserted  in  several  rows  into  the  base  of  a 
large  and  fleshy  obconical  torus,  deciduous.  Stamens  inserted  into 
the  torus  in  several  rows :  the  filaments  petaloid ;  the  anthers  ad- 
nate  and  introrse.  Carpels  several,  separately  immersed  in  hollows 
of  the  enlarged  flat-topped  torus  or  receptacle  (Fig.  427),  each  con- 
taining a  single  anatropous  ovule ;  in  fruit  forming  hard,  round  nuts. 
Seed  without  albumen :  embryo  very  large,  with  two  fleshy  cotyle- 
dons, and  a  highly  developed  plumule.  —  Ex.  The  order  consists  of 
the  single  genus  Nelumbium,  embracing  two  species  ;  one  a  native 
of  Asia,  the  other  of  North  America.  They  are  chiefly  remarkable 
for  their  large  and  showy  leaves  and  flowers.  The  nuts  are  eatable. 
It  should  be  regarded  rather  as  a  suborder  of  the  next. 

749.  Ol'd.  NymphaiacCfE  {Water-Lily  Family).  Aquatic  herbs,  with 
showy  flowers  and  cordate  or  peltate  leaves,  arising  from  a  prostrate 
trunk  or  rhizoma,  and  raised  on  long  stalks  above  the  water,  or 
floating  on  its  surface.  Calyx  and  corolla  of  several  or  numerous 
imbricated  sepals  and  petals,  which  gradually  pass  into  each  other ; 
persistent ;  the  latter  inserted  on  the  fleshy  torus  which  surrounds 

33 


386 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


or  partly  encloses  and  adheres  to  the  pistil ;  the  inner  series  gradu- 
ally changing  into  stamens.  Stamens  numerous,  in  several  rows, 
inserted  into  the  torus  with  or  above  the  petals  ;  many  of  the  outer 
filaments  petaloid  (Fig.  344),  the  adnate  anthers  introrse.  Fruit  in- 
dehiscent,  pulpy  when  ripe,  many-celled,  crowned  with  the  radiate 
stigmas  ;  the  anatropous  seeds  covering  the  spongy  dissepiments. 
Embryo  small,  enclosed  in  a  membranous  bag,  which  is  next  the 
hilum,  and  half  immersed  in  the  mealy  albumen.  Structure  of  the 
trunk  appearing  rather  endogenous  than  exogenous.  —  Ex.  Nym- 
phsea,  the  White  Water-Lily ;  Nuphar,  the  Yellow  Pond-Lily  ;  and 


the  magnificent  Victoria  of  tropical  South  America,  the  most  gigan- 
tic and  showy  of  aquatics,  both  as  to  its  flowers  and  its  leaves.  Mu- 
cilaginous plants,  with  slight  astringency ;  no  important  properties. 

750.  Ord.  CabombaccSB   {Water-shield  Family)  is  really  merely  a 
simplified  state  of  the  last,  with  only  one  series  of  sepals  and  petals, 

FIG.  677.  Open  flower,  with  a  flower-bud  and  leaf  of  the  White  Water-Lily  (Nymphasa 
odorata) ;  the  inner  petals  passing  into  stamens.  678.  A  flower  with  all  the  parts  around  the 
pistil  cut  away  except  one  of  the  petaloid  stamens,  one  intermediate,  and  one  proper  stamen. 
679.  An  inner  petal,  with  the  imperfect  rudiments  of  an  anther  at  the  tip.  680.  Transyerse 
section  of  an  ovary. 


EXOGENOUS    OK   DICOTYLEDONOUS    PLANTS. 


387 


definite  stamens,  or  nearly  so,  with  innate  anthers,  and  the  gynrcciuni 
of  few  apocarpous,  free,  and  few-ovuled  pistils  ;  the  ovules  chiefly  on 
the  dorsal  suture.     Brasenia  and  Cabomba  are  all  the  genera. 


751.  Ord.  SarmceniaCCiT  (Water-Pitcher Family).  Perennial  herbs, 
growing  in  bogs ;  the  (purplish  or  yellowish-green)  leaves  all  radical 
and  hollow,  pitcher-shaped  (Fig.  299,  300),  or  trumpet-shaped. 
Calyx  of  five  persistent  sepals,  with  three  small  bracts  at  its  base. 
Corolla  of  five  petals.  Stamens  numerous.  Summit  of  the  com- 
bined styles  very  large  and  petaloid,  five-angled,  covering  the  five- 
celled  ovai-y,  persistent.  Fruit  five-celled,  five-valved,  with  a  large 
placenta  projecting  from  the  axis  into  the  cells.  Seeds  numerous, 
albuminous,  with  a  small  embryo.  —  Sarracenia,  from  which  the 
above  character  is  taken,  was  the  only  known  genus  of  the  order, 
until  the  recent  discovery  of  Heliamphora  in  Guiana,  which  is  apeta- 
lous,  its  scape  bearing  several  flowers  ;  as  does  that  of  a  third  genus, 

FIG.  681.  Brasenia  peltata  (Water-shield);  the  lower  flower  with  the  floral  envelopes  and  a 
part  of  the  stamens  removed.  6S2.  A  magnified  stamen.  683.  A  magnified  carpel.  684.  The 
same,  divided  lengthwise,  showing  the  ovules  attached  to  the  outer  or  dorsal  suture !  C85.  Sec- 
tion of  a  carpel,  in  fruit.  686.  A  magnified  seed,  with  half  the  outer  integument  removed, 
displaying  at  the  upper  extremity  the  bag  which  contains  the  embryo.  687.  A  magnified  sec- 
tion through  the  middle  of  the  albumen,  &c.  ;  bringing  to  view  the  minute  embryo  enclosed 
in  its  sac,  lying  outside  of  the  albumen,  which  forma  the  principal  bulk  of  the  seed. 


388 


ILLUSTRATIONS    OF   THE    NATURAL    ORDERS. 


Darlingtonia,  Torr.,  recently  discovered  in  California,  Avith  calyx  and 
corolla  not  very  unlike  those  of  Sarracenia,  but  without  the  umbrella- 
like style.  The  species  of  Sarracenia  are  all  Eastern  North  Amer- 
ican.    The  affinities  of  the  group  are  unsettled. 

752.  Ord.  PapaveraceOB  (Poppy  Family).  Herbs  with  a  milky  or 
colored  juice,  and  alternate  leaves  without  stipules.  Calyx  of  two 
(rarely  three)  caducous  sepals.  Corolla  of  four  to  six  regular  petals. 
Stamens  eight  to  twenty-four,  or  numerous.  Fruit  one-celled,  with 
two  to  five  or  numerous  parietal  placentae,  from  which  the  valves 
often  separate  in  dehiscence.  Seeds  numerous,  with  a  minute  em- 
bryo, and  copious  fleshy  and  oily  albumen.  —  Ex.  The  Poppy  (Pa- 
paver),  the  leading  representative  of  this  small  but  important  family, 
is  remarkable  for  the  extension  of  the  placentas  so  as  almost  to  divide 


the  cavity  of  the  ovary  into  several  cells,  and  for  the  dehiscence  of 
the  capsule  by  mere  chinks  or  pores  under  the  edge  of  the  crown 

FIG.  688.  Sanguinaria  Canadensis  (the  Bloodroot).  689  The  pod,  divided  transversely, 
showing  the  parietal  attachment  of  the  seeds  690  Longitudinal  section  of  a  magnified  seed 
with  its  large  rhaphe,  showing  the  minute  embryo,  near  the  extremity  of  the  albumen. 
691.  Flower-bud  of  Eschscholtzia.  692.  The  calyptriforni  calyx  detached  from  the  base.  693. 
Pod  of  the  same. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS. 


389 


formed  by  the  radiate  stigmas.  Eschscholtzia,  now  common  in 
gardens,  is  remarkable  for  the  expanded  apex  of  the  peduncle,  and 
for  the  union  of  the  two  sepals  into  a  calyptra,  like  a  candle-extin- 
guisher, which,  separating  at  the  base,  is  thrown  off  by  the  expan- 
sion of  the  petals.  The  colored  juice  is  narcotic  and  stimulant. 
That  of  the  Poppy  yields  Opium.  That  of  the  Celandine  and  of  the 
Bloodroot  (Sanguinaria)  is  acrid. 

752'.  Ord.  FamariaceiC  {Fumitory  Family).  Smooth  herbs,  Avith 
brittle  stems,  and  a  watery  juice,  alternate  dissected  leaves,  and  no 
stipules.  Flowers  irregular.  Calyx  of  two  sepals.  Corolla  of  four 
petals,  in  pairs ;  the  two  outer,  or  one  of  them,  spurred  or  sac-like 
at  the  base ;  the  two  inner,  callous  and  cohering  at  the  apex,  includ- 
ing the  anthers  and  stigma.  Stamens  six,  in  two  parcels  opposite 
the  outer  petals  ;  the  filaments  of  each  set  usually  more  or  less 
united  ;  the  middle  one  bearing  a  two-celled  anther ;  the  lateral,  with 
one-celled  anthers.  Fruit  a  one-celled  and  two-valved  pod,  or  round 
and  indehiscent.  Seeds  with  fleshy  albumen  and  a  small  embryo.  — 
Ex.  Fumaria,  Dicentra  (Fig.  3G9-374),  Corydalis. 
A  small  and  unimportant  tribe  of  plants,  chiefly  re- 
markable for  their  singular  irregular  flowers ;  by 
which,  with  their  watery  juice,  they  are  distin- 
guished, and  that  not  very  definitely,  from  the  pre- 
ceding family. 

753.  Ord.  Crncifcra  {Mustard  Family).  Herbs, 
with  a  pungent  or  acrid  watery  juice,  and  alternate 
leaves  without  stipules  ;  the  flowers  in  racemes  or 
corymbs,  with  no  bracts  to  the  pedicels.  Calyx  of 
four  sepals,  deciduous.  Corolla  of  four  regular 
petals,  with  claws,  their  spreading  limbs  forming  a 
cross  (Fig.  694).  Stamens  six,  two  of  them  short- 
er {tetradynamous,  Fig.  695,  589).  Fruit  a  pod 
(called  a  silique  when  much  longer  than  broad,  or  a 
silicle  when  short,  Fig.  703),  winch  is  two-celled 
by  a  membranous  partition  that  unites  the  two 
marginal  placentae,  from  which  the  two  valves  usually  fall  away. 
Seeds  with  no  albumen  :  embryo  with  the  cotyledons  folded  on  the 
radicle.  —  Ex.  The  Water-Cress,  Radish,  Mustard,  Cabbage,  &c. 
A  very  natural  order,  perfectly  distinguished  by  having  six  tetra- 
dynamous stamens  along  Avith  four  petals  and  four  sepals,  and  by  the 

FIG.  694.  Flower  of  Mustard.    695.  The  stamens  and  pistil. 

33* 


390 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


peculiar  pod.  The  peculiarity  of  the  stamens  is  explained,  and 
the  singular  symmetry  of  the  flower  illustrated,  on  p.  243.  All 
these  plants  have  a  peculiar  volatile  acridity  (and  often  an  ethe- 
real oil,  which  abounds  in  sulphur)  dispersed  through  every  part, 
from  which  they  derive  their  peculiar  odor  and  sharp  taste,  and 
their  stimulant,  rubefacient,  and  antiscorbutic  properties.  The  roots 
of  some  perennial  species,  such  as  the  Horseradish,  or  the  seeds  of 
annual  species,  as  the  Mustard,  are  used  as  condiments.  In  some 
cultivated  plants,  the  acrid  principle  is  dispersed  among  abundance 
of  saccharine  and  mucilaginous  matter,  affording  wholesome  food ; 
as  the  root  of  the  Turnip  and  Radish,  and  the  leaves  and  stalks 


of   the    Cabbage    and    Cauliflower.      None    are    really    poisonous 
plants,  although  some   are    very   acrid.     Several    species    are    in 

FIG.  096.  A  Cruciferous  flower.  697.  The  same,  with  the  calyx  and  corolla  removed,  show- 
ing the  tetradynamous  stamens.  698.  Siliquts  of  Arabis  Canadensis  ;  one  of  them  with  one  of 
the  valves  detached,  showing  the  seeds  lying  on  the  false  partition ;  the  other  valve  also  falling 
away.  699.  A  magnified  cross-section  of  one  of  the  winged  seeds,  showing  the  embryo  with 
the  radicle  applied  to  the  edge  of  the  cotyledons  (cotyledons  accambent).  700.  The  embryo 
detached.  701.  The  raceme  of  Draba  verna,  in  fruit.  702.  A  cross-section  of  one  of  the  sili- 
cles,  magnified,  exhibiting  the  parietal  insertion  of  the  seeds,  and  the  false  partition.  703.  A 
silicle  of  Shepherd's  Purse  (Capsella  Bursa  Pastoris).  704.  The  same,  with  one  of  the  boat- 
shaped  valves  removed,  presenting  a  longitudinal  view  of  the  narrow  partition,  &c.  705.  A 
magnified  cross-section  of  one  of  the  seeds,  showing  the  embryo  with  the  radicle  applied  to  the 
side  of  the  cotyledon  (cotyledons  incumbent). 


EXOGENOUS    OK    DICOTYLEDONOUS    PLANTS. 


391 


cultivation,  for  their  beauty  or  fragrance  ;  such  as  the  Wall-flower, 
Stock,  &e. 

754.  Ord.  Cappai'idaceSG  {Caper  Family).  Herbs,  or  in  tbe  tropics 
often  shrubs  or  trees ;  differing  from  Cruciferae  in  the  one-celled  pod 
(which  is  often  stalked)  being  destitute  of  any  false  partition ;  in  the 
kidney-shaped  seeds ;  and  in  the  stamens,  which,  when  six,  are 
scarcely  tetradynarnous,  and  are  often  more  numerous.  —  Fx.  Cle- 
ome,  Polanisia,  Gynandropsis ;  chiefly  tropical  or  subtropical. 
Many  have  the  pungency  of  Cruciferre,  but  are  more  acrid.  Capers 
are  the  pickled  flowei'-buds  of  Capparis  spinosa  of  the  Levant,  &c. 
The  roots  and  herbage  or  bark  are  bitter,  nauseous,  and  sometimes 
poisonous. 

710  709 


755.  Ord.  Resedacea)  {Mignonette  Family).  Herbs,  with  a  watery 
juice,  and  alternate  leaves  without  stipules,  except  a  pair  of  glands 
be  so  considered :  the  flowers  in  terminal  racemes,  small,  and  often 
fragrant. —  Calyx  persistent,  of  four  to  seven  sepals,  somewhat 
united  at  the  base.  Corolla  of  two  to  seven  usually  unequal  and 
lacerated  petals,  with  broad  or  thickened  claws  (Fig.  377).  A 
fleshy  disk  is  commonly  present,  enlarged  posteriorly  between  the 
petals  and  the  stamens,  and  bearing  the  latter,  which  vary  from 
three  to  forty  in  number,  and  are  not  covered  by  the  petals  and 
sepals  in  the  bud.  Fruit  a  one-celled  pod,  with  three  to  six  parietal 
placenta?,  three  to  six-lobed  at  the  apex,  where  it  opens  along  the 

FIG.  706.  Flower  of  Gynandropsis.  707.  Flower  of  Polanisia  graveolens.  708.  Fructified 
ovary  of  the  same,  a  portion  cut  away  by  a  vertical  and  horizontal  section,  to  show  the  single 
cell  and  two  parietal  placentae.  709.  Cross-sectioa  of  the  ovary.  710.  Section  of  the  seed  and 
embryo. 


392 


ILLUSTRATIONS    OP   THE    NATURAL    ORDERS. 


inner  sutures,  usually  long  before  the  seeds  are  ripe.  Seeds  several 
or  many,  curved  or  kidney-sliaped,  •with,  no  albumen ;  the  embryo 
incurved.  —  Ex.  The  common  representatives  of  this  order  are  the 
Mignonette  (Reseda  odorata),  prized  for  its  fragrant  flowers,  and 
the  Weld  (R.  Luteola),  which  yields  a  poor  dye. 

75G.  Ord.  FlaCOUrtiacCfC,  a  group  of  tropical  shrubs  and  trees, 
placed  in  this  vicinity,  is  best  known  by  Bixa  Orellana,  which  yields 
Arnatto,  the  orange-red  dried  pulp  of  the  pod,  surrounding  the 
seeds. 

757.  Ord.  YiolaceSD  (  Violet  Family).  Herbs  (in  tropical  countries 
sometimes  shrubby  plants),  with  mostly  alternate  simple  leaves,  on 
petioles,  furnished  with  stipules;  and  irregular  flowers  (Fig.  896, 
397).  Calyx  of  five  persistent  sepals,  often  auricled  at  the  base. 
Corolla  of  five  unequal  petals,  one  of  them  larger  than  the  others 
and  commonly  bearing  a  spur  or  a  sac  at  the  base :  aestivation  imbri- 


cative.  Stamens  five,  with  short  and  broad  filaments,  which  are 
usually  elongated  beyond  the  (adnate  introrse)  anthers  ;  two  of 
them  commonly  bearing  a  gland  or  a  slender  appendage  which  is 
concealed  in  the  spur  of  the  corolla :  the  anthers  approaching  each 
other,  or  united  in  a  ring  or  tube.     Style  usually  turned  to  one  side 


FIG.  711.  Viola  sagittata.  712.  One  of  the  stamens  without  appendage,  seen  from  within  ; 
and  one  furnished  with  a  spur -like  appendage  on  the  back.  712a.  A  capsule  which  has  opened 
and  separated  into  three  valves ;  the  calyx  still  persistent.  712J.  A  vertical  section  of  the 
seed  and  embryo. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS. 


393 


and  thickened  at  the  apex.  Fruit  a  one-celled  capsule,  opening  by 
three  valves,  each  bearing  a  parietal  placenta  on  its  middle.  Seeds 
several  or  numerous,  anatropous,  with  a  crustaceous  integument,  and 
a  straight  embryo,  nearly  the  length  of  the  fleshy  albumen  (Fig.  G04, 
G05).  —  Ex.  The  Violet  is  the  principal  genus  of  this  order;  some 
species,  like  the  Pansy,  are  cultivated  for  the  beauty  of  their  flow- 
ers ;  others,  for  their  delicate  fragrance.  The  roots  of  all  are  acrid, 
and  emetic.  Those  of  some  South  American  species  of  Ionidium 
furnish  a  part  of  the  Ipecacuanha  of  commerce. 

758.  Ol'tl.  CistaceOB  {Rock-Rose  Family).  Low  shrubby  plants  or 
herbs,  with  simple  and  entire  leaves  (at  least  the  lower  opposite). 
Calyx  of  five  persistent  sepals ;  the  three  inner  with  a  convolute 
aestivation  ;  the  two  outer  small  or  sometimes  wanting.  Corolla  of 
five,  or  rarely  three,  regular  petals,  convolute  in  aestivation  in  the 
direction  contrary  to  that  of  the  sepals,  often  crumpled,  usually 
ephemeral,  sometimes  wanting,  at  least  a  portion  of  the  flowers. 
Stamens  few  or  numerous,  distinct,  with  short  innate  anthers.     Fruit 


a  one-celled  capsule  with  parietal  placentae,  or  imperfectly  three  to 
five-celled  by  dissepiments  arising  from  the  middle  of  the  valves 
(dehiscence  therefore  loculicidal),  and  bearing  the  placentae  at  or  near 
the  axis.     Seeds  few  or  numerous,  mostly  orthotropous,  with  mealy 


FIG.  713.  The  Rock-Rose,  Helianthemum  Canadense.  714.  Flower  from  -which  the  petals 
and  stamens  have  fallen.  715  Magnified  cross-section  of  the  ovary ;  with  a  single  stamen, 
showing  its  hypogynous  insertion.  716.  Cross-section  of  a  capsule,  loculicidally  dehiscent ; 
the  seeds  therefore  borne  on  the  middle  of  each  valve.  717.  An  ovule.  71S.  Plan  of  the 
flower.     719.  Section  of  a  seed,  showing  the  curved  embryo. 


394  ILLUSTRATIONS    OF   THE   NATURAL    ORDERS. 

albumen.  Embryo  curved,  or  variously  coiled  or  bent.  —  Ex.  Cistus, 
Helianthemum  :  a  small  family  ;  the  flowers  often  showy.  No  im- 
portant properties.  Several  exude  a  balsamic  resin,  such  as  Lada- 
num  from  a  Cistus  of  the  Levant. 

759.  Ol'd.  DroseraceSB  (Sundeio  Family).  Small  herbs,  growing  in 
swamps,  usually  covered  with  gland-bearing  hairs ;  with  the  leaves 
rolled  up  from  the  apex  to  the  base  in  vernation  (circinnate)  :  stip- 
ules none,  except  a  fringe  of  hairs  or  bristles  at  the  base  of  the 
petioles.  Calyx  of  five  equal  sepals,  persistent.  Corolla  of  five 
regular  petals,  withering  and  persistent,  convolute  in  aestivation. 
Stamens  as  many  as  the  petals  and  alternate  with  them,  or  some- 
times two  or  three  times  as  many,  distinct,  withering ;  anthers  ex- 
trorse.  Styles  three  to  five,  distinct  or  neaidy  so,  and  each  two- 
parted  (so  as  to  be  taken  for  ten  styles,  Fig.  510),  and  these  divis- 
ions sometimes  two-lobed  or  many-cleft  at  the  apex.  Fruit  a  one- 
celled  capsule,  opening  loculicidally  by  three  to  five  valves,  with 
three  to  five  parietal  placenta? ;  in  Dionaea  membranaceous,  burst- 
ing irregularly,  and  with  a  thick  placenta  at  the  base.  Seeds  usu- 
ally numerous.  Embryo  small,  at  the  base  of  cartilaginous  or  fleshy 
albumen.  —  Ex.  Drosera,  the  Sundew  ;  and  Dionaea  (Venus's  Fly- 
trap, Fig.  297,  298),  so  remarkable  for  its  sensitive  leaves,  which 
suddenly  close  when  touched.  The  styles  of  the  latter  are  all  united 
into  one. 

760.  Ol'd.  PamaSSiacCBB  is  for  the  present  made  for  the  genus  Par- 
nassia,  which  was  formerly  appended  to  Droseraceoe  (for  no  good 
reason),  and  has  since  been  placed  by  some  next  to  Hypericaceae,  by 
others  referred  to  Saxifragaceas.  It  is  remarkable  for  having  the 
four  or  five  stigmas  situated  directly  over  the  pai-ietal  placentae  (p. 
294,  note),  and  for  the  curious  appendages  resembling  sterile  sta- 
mens before  each  petal  (Fig.  380,  381). 

761.  Ol'd.  IlypericaceBE  (St.  Johnsioort  Family).  Shrubs  or  herbs, 
with  a  resinous  or  limpid  juice,  and  opposite  entire  leaves,  destitute 
of  stipules,  and  punctate  with  pellucid  or  blackish  dots.  Flowers 
regular.  Calyx  of  four  or  five  persistent  sepals,  the  two  exterior 
often  smaller.  Petals  four  or  five,  convolute  in  aestivation,  often 
beset  with  black  dots.  Stamens  commonly  polyadelphous  and  numer- 
ous. Ovary  one-celled  with  parietal  placentae,  or  4  -  5-celled  (Fig. 
375,  497,  498,  508,  509).  Capsule  with  septicidal  dehiscence  (Fig. 
582),  many-seeded.  —  Ex.  Hypericum  (St.  Johnswort)  is  the  type 
of  this  small  family.     Embryo  straight ;    albumen   little  or   none. 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


395 


The  plants  yield  a  resinous  acrid  juice,  and  a  bitter,  balsamic  ex- 
tractive matter. 


762.  Ord.  Elaliliacca:  (Waterwort  Family).  Small  annual  weeds 
with  membranaceous  stipules  between  the  opposite  leaves,  and  mi- 
nute axillary  flowers.  Sepals  and  petals  three  to  five.  Stamens  as 
many  or  twice  as  many  as  the  petals,  distinct.  Capsule  2  —  5-celled, 
septicidal  or  septifragal ;  the  numerous  seeds  attached  to  a  persist- 
ent central  axis.  Albumen  none.  —  Ex.  Elatine  is  the  type  of  this 
order,  containing  a  few  insignificant  weeds. 

763.  Ord.  Caryopliyllaceae  (Fink  Family).  Herbs,  with  opposite 
entire  leaves ;  the  stems  tumid  at  the  nodes.  Flowers  regular. 
Calyx  of  four  or  five  sepals.  Corolla  of  four  or  five  petals,  or 
sometimes  wanting.  Stamens  as  many,  or  commonly  twice  as  many, 
as  the  petals,  sometimes  reduced  to  two  or  three.  Styles  two  to 
five,  stigmatose  down  the  inside.  Ovary  mostly  one-celled,  with  a 
central  or  basilar  placenta,  forming  a  pod  in  fruit.  Embryo  periph- 
eric, curved  or  coiled  around  the  outside  of  mealy  albumen  (Fig. 
620,  621,  726).  —  There  are  five  principal  suborders,  viz. :  — 

764.  Subord.  SileilCflB  {Pink  Family  proper)  ;  in  which  the  sepals 
are  united  into  a  tube,  and  the  petals  (mostly  convolute  in  aestiva- 
tion) and  stamens  are  inserted  on  the  stipe  of  the  ovary,  the  former 
with  long  claws  (Fig.  432,  449),  and  there  are  no  stipules.  —  Ex. 
Silene,  Dianthus  (Pink,  Carnation). 

765.  Subord.  Alsilieae  (Chickweed  Family) ;  in  which  there  are  no 


FIG.  720.     Hypericum  perforatum   (St.  Johnswort).     721.    Its  tricarpellary  pistil. 
Cross-section  of  the  capsule.     723.  Vertical  section  of  a  seed  and  its  embryo. 


722. 


396 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


stipules,  the  ovary  is  sessile,  the  sepals  and  petals  (imbricated  in 
aestivation)  are  nearly  or  quite  distinct ;  the  petals  destitute  of  claws  ; 
and  the  stamens  are  inserted  into  the  margin  of  a  small  hypogynous 
disk,  which,  however,  occasionally  coheres  with  the  base  of  the  calyx, 
and  becomes  perigynous.  —  Ex.  Stellaria,  Arenaria,  &c.  (Chick- 
weeds).  Some  are 
ornamental ;  others, 
such  as  the  common 
Chickweed,  are  in- 
significant weeds. 

766.  Subord.  Ille- 
cebrecD  {Knot  wort 
Family)  ;  differing 
from  the  last  main- 
ly in  having  sca- 
rious  stipules  ;  the 
sepals  often  united 
below  ;  the  petals 
often  wanting  or  ru- 
dimentary ;  the  sta- 
mens manifestly  pe- 
rigynous ;  and  the 
fruit  more  commonly 
a  one-seeded  utricle  —  Ex.  Paronychia  and  Anychia.  Spergula  has 
conspicuous  petals,  and  many-seeded  capsules ;  and  so  differs  from 
Alsineos  only  in  its  stipules.     Insignificant  weeds. 

767.  Subord.  SclerantheCB  {Knawel  Family)  is  like  the  last,  only 
there  are  no  stipules.  —  Ex.  Scleranthus. 

768.  Subord.  MolluginCiE  {Carpet-weed  Family)  is  apetalous  with- 
out stipules,  and  has  the  stamens  alternate  with  the  sepals  when  of 
the  same  number  ;  thus  effecting  a  transition  to 

769.  Ol'd.  Poi'tulacaccSB  {Purslane  Family).  Succulent  or  fleshy 
herbs,  with  entire  exstipulate  leaves  and  usually  ephemeral  flowers. 
Calyx  mostly  of  two  or  three  sepals,  sometimes  cohering  with  the 
base  of  the  ovary.  Petals  five,  or  rarely  more  numerous,  sometimes 
none.  Stamens  variable  in  number,  but  when  equal  to  the  petals 
situated  opposite  them.     Styles  two  to  eight,  united  below.     Capsule 

FIG.  724.  Moehringia  lateriflora.  725.  A  magnified  flower.  726.  Magnified  section  of  a 
seed,  showing  the  embryo  coiled  into  a  ring  around  the  albumen.  727.  A'ertical  section  of  a 
pistil  of  Spergularia. 


EXOGENOUS    OR   DICOTYLEDONOUS    TLANTS. 


397 


with  few  or  numerous  seeds,  attached  to  a  central  basilar  placenta, 
often  by  slender  funiculi.  Seed  and  embryo  as  in  Caryophyllaceoe. 
—  Ex.  Portulaca  (Purslane,  Fig.  389,  588)  Claytonia.  Chiefly 
natives  of  dry  places  in  the  warmer  parts  of  the  world ;  except 
Claytonia.  Insipid  or  slightly  bitter :  several  are  pot-herbs,  as  the 
Purslane.     Some  are  ornamental.     The  farinaceous  root  of  Lewisia 


rediviva,  a  native  of  the  dry  interior  plains  of  Oregon,  is  an  impor- 
tant article  of  food  with  the  natives. 

770.  Ord.  MesembryantliemacCEB  {Fig-Marigold  Family)  consists  of 
succulent  plants,  with  showy  flowers  opening  only  under  bright  sun- 
shine, containing  an  indefinite  number  of  petals  and  stamens,  and  a 
many-celled  and  many-seeded  capsule :  otherwise  much  as  in  Caryo- 
phyllaceae.  —  Ex.  Mesembryanthemum  (Fig-Marigold,  Ice-plant)  ; 
chiefly  natives  of  the  Cape  of  Good  Hope,  flourishing  in  the  most 
arid  situations. 

771.  Ord.  Malvaceae  {Mallow  Family).  Herbs,  shrubs,  or  rarely 
trees.  Leaves  alternate,  palmately  veined,  with  stipules.  Flowers 
regular,  often  with  an  involucel,  forming  a  double  calyx.  Calyx 
mostly  of  five  sepals,  more  or  less  united  at  the  base,  valvate  in 

FIG.  728.  Flower  of  the  Purslane ;  the  calyx  cut  away  at  the  point  where  it  adheres  to  the 
ovary,  and  laid  open.  729.  A  capsule  (pyxis)  of  the  same,  transversely  dehiscent.  730.  Clay- 
tonia Yirginica  (Spring-Beauty).  731.  Diagram  of  the  flower.  732.  Young  fruit  and  the  per- 
sistent two-leaved  calyx.  733.  Section  of  the  dehiscing  capsule.  734.  A  seed.  735.  The 
same,  vertically  divided.     736.  The  embryo,  detached. 

34 


398 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


aestivation.  Petals  as  many  as  the  sepals,  convolute  in  aestivation, 
hypogynous.  Stamens  indefinite,  monadelphous,  united  with  the 
claws  of  the  petals  :  anthers  reniform,  confluently  one-celled.  Pollen 
hispid  (Fig.  483).  Ovary  several-celled,  with  the  placenta?  in  the 
axis;  or  ovaries  several.  Fruit  capsular,  or  the  carpels  separate 
or  separable.  Seeds  with  a  little  mucilaginous  or  fleshy  albumen. 
Embryo  large,  with   foliaceous    cotyledons,  variously  incurved    or 


folded.  —  Ex.  Malva  (Mallow),  Althaea  (Hollyhock),  Gossypium 
(Cotton),  &c. :  a  rather  large  and  important  family,  the  herbage, 
&c.  commonly  abounding  in  mucilage,  and  entirely  destitute  of  un- 
wholesome qualities.  The  unripe  fruit  of  Abelmoschus  or  Hibiscus 
esculentus  (Okra)  is  used  in  soups.  Althaea  officinalis  is  the  Marsh 
Mallow  of  Europe,  the  Guimauve  of  the  French.  The  tenacious 
inner  bark  of  many  species  is  employed  for  cordage.  Cotton  is  the 
hairy  covering  of  the  seeds  of  Gossypium :  the  long  and  slender 
tubes,  or  attenuated  cells,  collapse  and  twist  as  the  seed  ripens, 
which  renders  the  substance  capable  of  being  spun.  Cotton-seed 
yields  a  good  fixed  oil.  Some  species  are  cultivated  for  ornament. 
772.  Ofd.  Byttnci'iacece  is  distinguished  from  the  foregoing  by  its 
usually  definite  stamens,  and  the  two-celled  anthers  (the  cells  par- 
allel), with  smooth  pollen.  —  A  Melochia  and  a  Hermannia  are 
found  in  Texas.  The  rest  of  the  order  is  tropical  or  subtropical. 
Chocolate  is  made  of  the  roasted  and  comminuted  seeds  of  Theo- 
brorna  Cacao  (a  South  American  tree),  mixed  with  sugar,  arnotto, 
vanilla,  and  other  ingredients.  The  roasted  integuments  of  the  seeds, 
also,  are  used  as  a  substitute  for  coffee. 


FIG.  737.  The  Marsh  Mallow  (Althaea  officinalis).  738.  One  of  the  kidney-shaped  one-celled 
anthers,  magnified.  739.  The  pistils,  magnified.  740.  Capsule  of  Hibiscus  Moscheutos,  with 
the  persistent  calyx  and  involucel.    741.  The  same,  loculicidally  dehiscent. 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


399 


773.  Orel.  SterCllIiacefC,  very  closely  allied  to  the  last  two,  and  con- 
sisting of  tropical  trees,  possesses  the  same  mucilaginous  properties 
(as  well  as  oily  seeds),  with  which  bitter  and  astringent  qualities  are 
often  combined.  The  seeds  of  Bombax,  the  Silk-cotton  tree,  are 
enveloped  in  a  kind  of  cotton,  which  belongs  to  the  endocarp  and 
not  to  the  seed ;  and  the  hairs,  being  perfectly  smooth  and  even,  can- 
not be  spun.  Canoes  are  made  from  the  trunk  of  the  huge  Bombax 
Ceiba,  in  the  West  Indies.  To  this  order  belongs  the  famous 
Baobab,  or  Monkey-bread,  of  Senegal  (Adansonia  digitata),  some 
trunks  of  which  are  from  sixty  to  eighty  feet  in  circumference ! 
The  fruit  resembles  a  gourd,  and  serves  for  vessels ;  it  contains  a 
subacid  and  refrigerant,  somewhat  astringent  pulp ;  the  mucilagi- 
nous young  leaves  are  also  used  for  food  in  time  of  scarcity ;  the 
dried  leaves  (Lalo)  are  ordinarily  mixed  with  food,  and  the  bark 
furnishes  a  coarse  thread,  which  is  made  into  cordage  or  woven  into 
cloth.  Cheirostemon  platanoides  is  the  remarkable  Hand-flower 
tree  of  Mexico.  A  plant  of  the  family  (Fremontia,  Torr.)  nearly 
allied  to  Cheirostemon  has  been  found  in  California,  by  Fremont. 

774.  Ord.  TiliaceOB  {Linden  Family).  Trees  or  shrubby  plants, 
with  alternate  leaves,  furnished  with  deciduous  stipules,  and  small 


jjJ<I-N*K,, 


flowers.     Calyx  deciduous.     Petals  sometimes  imbricated  in  restiva- 

FIG.  742.  Flowering  branch  of  Tilia  Americana,  the  common  American  Linden ;  the  flower- 
stalk  cohering  with  the  bract.  743.  One  of  the  clusters  of  stamens  adhering  to  the  petajoid 
scale.  744.  The  pistil.  745.  Cross-section  of  the  fruit,  which  has  become  one-celled  by  the 
obliteration  of  the  partitions,  and  one-seeded.  746.  Vertical  section  of  the  seed,  magnified,  to 
show  the  large  embryo  with  its  taper  radicle  and  foliaceous  crumpled  cotyledons.  (A  better 
section  of  the  seed,  cut  in  the  direction  across  the  cotyledons,  is  shown  in  Fig.  599.)  747. 
Diagram  of  the  flower. 


400  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

tion.  Stamens  indefinite,  often  in  three  to  five  clusters,  distinct  or 
somewhat  united,  one  of  each  parcel  often  transformed  into  a  peta- 
loid  scale  (Fig.  383,  743)  :  anthers  two-celled.  Styles  united  into 
one.  Fruit  two  to  five-celled,  or,  by  obliteration,  one-celled  when 
ripe.  In  other  respects  nearly  as  in  Malvaceae.  —  Tilia,  the  Linden, 
or  Lime-Tree,  represents  the  order  in  northern  temperate  regions ; 
the  other  genera  are  tropical.  All  are  mucilaginous,  with  a  tough 
fibrous  inner  bark.  From  this  bast  or  bass  of  the  Linden,  the  Rus- 
sian mats,  &c.  ai-e  made,  whence  the  name  of  Basswood.  Gunny- 
ba£s  and  fishing-nets  are  made  in  India  from  the  bark  of  Corchorus 
capsularis  ;  the  fibre  of  which,  called  Jute,  is  spun  and  woven.  The 
light  wood  of  the  Linden  is  excellent  for  wainscoting  and  carv- 
ing :  its  charcoal  is  used  for  the  manufacture  of  gunpowder.  It  is 
said  that  a  little  sugar  may  be  obtained  from  the  sap  :  and  the  honey 
made  from  the  odorous  flowers  is  thought  to  be  the  finest  in  the 
world.  The  acid  berries  of  Grcwia  sapida  are  employed  in  the 
East  in  the  manufacture  of  sherbet.  . 

775.  Ord.  DiptcrocarpCEC,  allied  in  some  respects  to  Tiliaceae,  con- 
sists of  a  few  tropical  Indian  trees,  with  a  resinous  or  balsamic  juice. 
Dryobalanops  aromatica,  a  large  tree  of  Sumatra  and  Borneo,  yields 
in  great  abundance  camphor  oil  and  solid  camphor :  both  are  found 
deposited  in  cavities  of  the  trunk.  It  is  more  solid  than  common 
camphor,  and  is  not  volatile  at  ordinary  temperatures.  It  bears  a 
high  price,  and  is  seldom  found  in  Europe  or  this  country,  but  is 
chiefly  carried  to  China  and  Japan.  Shorea  robusta  yields  the 
Dammer-pitch.  Vateria  Indica  exudes  a  kind  of  copal,  the  Gum 
Animi  of  commerce ;  and  a  somewhat  aromatic  fatty  matter,  called 
Piney  Tallow,  is  derived  from  the  seeds. 

776.  Ord.  Gllttiferac,  or  ClusiaceaB,  consists  of  tropical  trees,  with  a 
yellow  resinous  juice,  opposite  and  coriaceous  entire  leaves,  and 
large  flowers  with  many  stamens,  little  distinction  between  the 
sepals  and  petals,  no  styles,  an  indehiscent  fruit,  and  seeds  with  a 
peculiar  undivided  fleshy  embryo.  It  has  been  associated  with  Hy- 
pericaceae,  but  is  more  related  to  the  ensuing  families.  The  resin- 
ous juice  is  acrid  and  drastic  ;  that  of  a  Ceylonese  tree  of  the  order 
yields  Gamboge.  It  is  remarkable  that  such  an  order  should  pro- 
duce one  of  the  most  esteemed  fruits,  viz.  the  Mangosteen,  yielded  by 
Garcinia  Mangostana  of  Malacca,  and  also  the  Mammee-apple,  &c. 

777.  Ol'd.  CamelliaceiC  {Camellia  or  Tea  Family).  Trees  or  shrubs, 
with  a  watery  juice,  alternate  simple  leaves  without  stipules,  and 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS.  401 

large  and  showy  flowers.  Calyx  of  three  to  seven  coriaceous  and 
concave  imbricated  sepals.  Petals  five  or  more,  imbricated  in  aesti- 
vation. Stamens  hypogynous,  indefinite,  monadelphous  or  polyadel- 
phous at  the  base.  Capsule  dehiscent,  several-celled,  usually  with  a 
central  column.  Seeds  few  in  each  cell,  large,  often  winged,  with 
or  without  albumen.  —  The  Camellia  and  the  closely  related  Tea- 
plant  form  the  type  of  this  family,  to  which  belong  our  Gordonia 
and  Stuartia.  The  leaves  of  Tea  contain  a  peculiar  extractive  mat- 
ter, and  an  ethereal  oil ;  its  moderately  stimulant  properties  are 
said  to  become  narcotic  in  very  hot  climates. 

778.  Ord.  TernstrffimiaCCiJe,  chiefly  tropical,  with  which  the  last  has 
been  confounded,  by  its  aspect,  its  commonly  polygamous  flowers, 
and  more  or  less  gamopetalous  corolla,  &c,  appears  on  the  whole 
to  be  more  allied  to  the  Ebenaceoe  and  Symplocinese. 

779.  Ol'd.  AlirantiaceDE  {Orange  Family).  Trees  or  shrubs,  with 
alternate  leaves  (compound,  or  with  jointed  petioles),  destitute  of 
stipules,  dotted  with  pellucid  glands  full  of  volatile  oil.  Flowers 
fragrant.  Calyx  short,  urceolate  or  campanulate.  Petals  three  to 
five.  Stamens  inserted  in  a  single  row  upon  a  hypogynous  disk 
(Fig.  434),  often  somewhat  monadelphous  or  polyadelphous.  Style 
cylindrical.  Fruit  a  many-celled  berry,  with  a  leathery  rind,  filled 
with  pulp.  Seeds  without  albumen.  —  Ex.  Citrus,  the  Orange  and 
Lemon.  Nearly  all  natives  of  tropical  Asia ;  now  dispersed  through- 
out the  warmer  regions  of  the  world,  and  cultivated  for  their  beauty 
and  fragrance,  and  for  their  grateful  fruit.  The  acid  of  the  Lemon, 
Lime,  &c.  is  the  citric  and  the  malic.  The  rind  abounds  in  a  vola- 
tile oil  (such  as  the  Oil  of  Bergamot  from  C.  Limetta),  and  an  aro- 
matic, bitter  principle. 

780.  Ol'd.  MeliaCGCP.  Trees  or  shrubs,  with  alternate,  usually  com- 
pound leaves,  destitute  of  stipules.  Calyx  of  three  to  five  sepals. 
Petals  three  to  five.  Stamens  twice  as  many  as  the  petals,  mona- 
delphous, inserted  with  the  petals  on  the  outside  of  an  hypogynous 
disk  ;  the  anthers  included  in  the  tube  of  filaments.  Ovary  several- 
celled,  with  one  or  two  ovules  in  each  cell :  styles  and  stigmas  united 
into  one.  Fruit  a  drupe,  berry,  or  capsule ;  the  cells  one-seeded. 
Seeds  without  albumen,  wingless.  —  Ex.  Melia  Azedarach  (Pride  of 
India),  naturalized,  as  an  ornamental  tree,  in  the  Southern  States. 
An  acrid  and  bitter  principle  pervades  this  tropical  order. 

781.  Ord.  Cedrelaeese  (Mahogany  Family).  Trees  (tropical  or 
Australian),  with  hard  and  durable,  usually  fragrant  and  beautiful 

34* 


402 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


wood  ;  differing  botanically  from  Meliacere  chiefly  by  their  capsular 
fruit,  with  several  winged  seeds  in  each  cell.  —  Ex.  The  Mahogany 
(Swietenia  Mahagoni)  of  tropical  America,  reaching  to  East  Flor- 
ida. Bark,  &c.  bitter,  astringent,  tonic,  often  aromatic  and  febrifugal. 
782.  Ol'd.  Liliacete  {Flax  Family).  Herbs,  with  entire  and  sessile 
leaves,  either  alternate,  opposite,  or  verticillate,  and  no  stipules,  ex- 
cept minute  glands.  Flowers  regular  and  symmetrical.  Calyx  of 
three  or  five  persistent  sepals,  strongly  imbricated.  Petals  as  many 
as  the  sepals,  convolute  in  aestivation.  Stamens  as  many  as  the 
petals,  and  usually  with  as  many  intermediate  teeth  representing  an 
abortive  series  (Fig.  423),  all  united  at  the  base  into  a  ring,  hypogy- 


nous.  Ovary  with  as  many  styles  and  cells  as  there  are  sepals, 
each  cell  with  two  suspended  ovules  ;  the  cells  in  the  capsule  each 
more  or  less  divided  into  two,  by  a  false  par- 
tition which  grows  from  the  back  (Fig.  750)  ; 
the  spurious  cells 
one-seeded.  Em- 
bryo straight : 
cotyledons  flat, 
fleshy  and  oily, 
750  surrounded  by  a 

thin  albumen.  —  Ex.  Linum,  the  Flax, 
the  bark  {flax)  is  of  the  highest  importance :  the  seeds  yield  a 
copious  mucilage,  and  the  fixed  oil  expressed  from  them  is  applied 
to  various  uses  in  the  arts.  The  general  plan  of  the  flower  is  the 
same  in  the  succeeding  orders. 


The  tough  woody  fibre  of 


FIG.  748.  Flowers  of  the  common  Flax.  749.  Vertical  section  of  a  flower.  7D0.  Diagram 
of  the  same,  in  a  transverse  section.  751.  Its  10-celled  capsule  transversely  divided.  752. 
Similar  section  of  the  incompletely  10-celled  capsule  of  Linum  perenne. 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


403 


783.  Ord.  GcraniaceOB  (OranesbiU  Family).  Herbs  or  shrubby 
plants,  commonly  strong-scented ;  with  palmately  veined  and  usually 
lobed  leaves,  mostly  with  stipules  ;  the  lower  opposite.  Flowers 
regular.  —  Calyx  of  five  persistent  sepals,  imbricated  in  aestivation. 
Petals  five,  with  claws,  mostly  convolute  in  aestivation.  Stamens  10, 
the  five  exterior  hypogynous,  occasionally  sterile ;  the  filaments  all 
broad  and  often  united  at  the  base ;  five  glands  within  and  alternate 
with  the  petals.  Ovary  of  five  two-ovuled  carpels,  attached  to  the 
base  of  an  elongated  axis  (gynobase,  Fig.  430,  431)  to  which  the 
styles  cohere  :  in  fruit  the  distinct  one-seeded  carpels  separate  from 
the  axis,  by  the  twisting  or  curling  back  of  the  persistent  indurated 


styles  from  the  base  upwards.  Seeds  with  no  albumen  :  cotyledons 
convolute  and  plaited  together,  bent  on  the  short  radicle.  For  the 
plan  of  the  blossom  see  p.  264,  and  Fig.  421.  Our  cultivated 
Geraniums,  so  called,  from  the  Cape  of  Good  Hope,  are  species  of 
Pelargonium.  The  roots  are  simply  and  strongly  astringent.  The 
foliage  abounds  with  resinous  matter  and  an  ethereal  oil,  on  which 
the  aroma  depends. 

784.  Ord.  BalsamilMCCae  {Balsam  Family).  Annual  herbs,  with 
succulent  stems  filled  with  a  watery  juice.  Leaves  simple,  without 
stipules.  Flowers  irregular,  and  one  of  the  colored  sepals  spurred 
or    saccate.      Stamens    five,  cohering   by   an   internal   appendage. 

FIG.  753.  Radical  leaf  of  Geranium  maculatum  (Cranesbill).  754.  A  flowering  branch. 
755.  A  flower  with  the  calyx  and  corolla  removed,  showing  the  stamens,  &c.  75G.  The  pistil 
in  fruit ;  the  indurated  styles  separating  below  from  the  prolonged  axis,  and  curving  back 
elastic  ally,  carrying  with  them  the  membranous  carpels.  757.  A  magnified  seed.  758.  A 
cross-section  of  the  same,  showing  the  folded  and  convolute  cotyledons. 


404  ILLUSTRATIONS    OF   THE   NATURAL    ORDERS. 

Compound  ovary  five-celled;  stigmas  sessile.  Capsule  bursting 
elastically  by  five  valves.  Seeds  several,  without  albumen,  and  with 
a  thick  straight  embryo.  —  Ex.  Impatiens,  the  Balsam,  or  Touch- 
me-not.  Remarkable  for  the  elastic  force  with  which  the  capsule 
bursts  in  pieces,  and  expels  the  seeds.  Somewhat  differently  irreg- 
ular blossoms  are  presented  by  the 

785.  Ord.  TropSCOlaceEB  {Indian-Cress  or  Nasturtium  Family). 
Straggling  or  twining  herbs,  with  a  pungent  watery  juice,  and  peltate 
or  palmate  leaves.  Flowers  irregular.  Calyx  of  five  colored  and 
united  sepals,  the  lower  one  spurred.  Petals  five ;  the  two  upper 
arising  from  the  throat  of  the  calyx,  remote  from  the  three  lower, 
which  are  stalked.  Stamens  eight,  unequal,  distinct.  Ovary  three- 
lobed,  composed  of  three  united  carpels  ;  which  separate  from  the 
common  axis  when  ripe,  are  indehiscent,  and  one-seeded.  Seed 
filling  the  cell,  without  albumen :  cotyledons  very  large  and  thick.  — 
Ex.  Tropasolum,  the  Garden  Nasturtium,  from  South  America, 
where  there  are  a  few  other  species,  one  of  which  beai*s  edible  tubers. 
They  possess  the  same  acrid  principle  and  antiscorbutic  properties 
as  the  Cruciferog.  The  unripe  fruit  of  Tropasolurn  majus  is  jnckled, 
and  used  as  a  substitute  for  capers. 

786.  Ord.  LimnanthaceiE  differs  from  the  last  only  in  its  regular  and 
symmetrical  blossoms,  and  the  erect  instead  of  suspended  seeds  ;  the 
calyx  valvate  in  aestivation.  —  Ex.  Limnanthes  of  California  (some- 
times cultivated  as  an  ornamental  annual),  and  Floerkea  of  the 
Northern  United  States. 

787.  Ord.  Oxalidaceffi  {Wood-Sorrel  Family).  Low  herbs,  with  an 
acid  juice,  and  alternate  compound  leaves ;  the  leaflets  usually  ob- 
cordate.  Flowers  regular,  of  the  same  general  structure  as  in  Li- 
naceae,  &c,  except  the  gynascium,  which  in  fruit  forms  a  membra- 
naceous five-lobed  and  five-celled,  several-seeded  capsule.  Seeds 
with  a  fleshy  outer  coat,  which  bursts  elastically  when  ripe,  with  a 
large  and  straight  embryo  in  thin  albumen.  —  Ex.  Oxalis,  the 
Wood-Sorrel.  The  herbage  is  sour,  as  the  name  denotes,  and  con- 
tains oxalic  acid.  The  foliage  is  remarkably  sensitive  in  some  spe- 
cies. The  tubers  of  some  South  American  species,  filled  with  starch, 
have  been  substituted  for  potatoes. 

788.  Ord.  ZygOphyllaceflB  differs  from  the  last  in  the  opposite, 
mostly  abruptly  pinnate  leaves,  distinct  stamens  (the  filaments  com- 
monly furnished  with  an  internal  scale,  Fig.  379),  and  the  styles 
united  into  one. — Ex.  Tribulus  and  Kallstroemia  (introduced  into 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


405 


the  Southern  States)  are  exalbuminous ;  the  latter  is  10-coccous, 
just  as  Linura  is,  by  a  false  partition.  Guaiacum,  Larrea  (Creo- 
sote-plant of  New  Mexico  and  Texas),  and  the  rest  of  the  family, 
have  a  corneous  albumen.  The  wood  of  Guaiacum  (Lignum-vitee) 
is  extremely  hard  and  heavy,  and  yields  a  gum-resinous,  bitter,  and 
acrid  principle  (Gum  Guaiacum),  well  known  in  medicine. 

789.  Ord.  SimarubaceSE  (Quassia  Family),  of  tropical  shrubs  or 
trees,  resembles  the  last  in  generally  having  a  peculiar  scale  to  the 
filaments.  It  is,  however,  more  nearly  related  to  the  next  order, 
but  its  apocarpous  ovaries  are  one-ovuled,  and  the  (mostly  com- 
pound) leaves  are  dotless.  The  wood,  &c.  is  intensely  bitter :  that 
of  Quassia  amara  is  used  as  a  stomachic  tonic.  The  seed  of  Cedron 
(Simaba  Cedron)  is  the  famous  antidote  for  the  bites  of  venomous 
snakes  in  Central  America. 

790.  Ord.  RutaceflB  (Rue  Family).  Herbs,  shrubs,  or  trees  ;  the 
leaves  punctate  with  pellucid  dots,  and  without  stipules.  Calyx  of 
four  or  five  sepals.     Petals  four  or  five,  or  rarely  none.     Stamens 


as  many  or  twice  (rarely  three  times)  as  many  as  the  petals,  insert- 

FIG.  759.  A  flowering  branch  of  Zanthoxylum  Americanum  (the  Northern  Prickly  Ash). 
760.  A  piece  of  a  leaf,  to  show  the  pellucid  dots.  761.  Staminate  flower.  762.  A  pistillate 
flower,  the  sepals  spread  open.  763.  Two  of  the  pistils ;  one  of  them  divided  vertically  to  show 
the  ovules.  764.  A  branch  in  fruit.  765.  One  of  the  dehiscent  pods,  and  the  seed.  766.  Ver- 
tical section  of  an  unripe  pod  and  seed ;  the  latter  pendent  from  a  descending  funiculus,  show- 
ing a  slender  embryo  in  copious  albumen. 


406  ILLUSTRATIONS    OF   THE    NATURAL    ORDERS. 

ed  on  the  outside  of  a  hypogynous  disk.  Ovary  three-  to  five-lobed, 
three-  to  five-celled,  with  the  styles  united,  or  distinct  only  at  the 
base,  or  the  ovaries  nearly  separate,  during  ripening  usually  sepa- 
rating into  its  component  carpels,  which  are  dehiscent  by  one  or 
both  sutures.  Seeds  few  or  single,  mostly  with  albumen ;  and  a 
curved  embryo.  —  Ex.  Ruta  (the  Rue),  Dictamnus  (Fraxinella),  of 
Europe.  Diosma  and  its  allies,  of  the  Cape  of  Good  Hope,  New 
Holland,  &c,  form  a  group,  or  suborder  (Diosme^e)  from  which  the 
ZANTHOXYLEiE  (or  Prickly-Ash  Family)  differs  only  in  being  gen- 
erally dioecious  ;  but  have  no  claim  to  be  ranked  as  a  distinct  order. 
Strong-scented,  bitter-aromatic,  often  very  pungent,  from  an  acrid 
volatile  oil  (as  Rue  and  Zanthoxylum)  ;  also  bitter.  Some  contain 
a  bitter  alkaloid,  and  are  febrifugal.  The  most  important  is  the 
Galipea,  which  furnishes  the  Angostura  bark. 

791.  Ol'd.  AnacardiacCiE  (Cashew  Family).  Trees  or  shrubs,  with 
a  resinous  or  milky,  often  acrid  juice,  which  turns  blackish  in  dry- 
ing ;  the  leaves  alternate,  without  stipules,  and  not  dotted.  Flowers 
small,  often  polygamous  or  dioecious.  Calyx  of  three  to  five  sepals, 
united  at  the  base.  Petals,  and  usually  the  stamens,  as  many  as  the 
sepals,  inserted  into  the  base  of  the  calyx  or  into  an  hypogynous  disk. 
Ovary  one-celled,  but  with  three  styles  or  stigmas,  and  a  single  ovule. 
Fruit  a  berry  or  drupe.  Seed  without  albumen.  Embryo  curved 
or  bent.  —  Ex.  Rhus,  Anacardium  (the  Cashew),  Pistacia.  Chiefly 
tropical ;  except  Rhus.  The  acrid  resinous  juice  is  used  in  var- 
nishes ;  but  it  often  contains  a  caustic  poison.  Even  the  exhalations 
from  Rhus  Toxicodendron  (Poison  Oak,  Poison  Ivy),  and  R.  vene- 
nata (Poison  Sumach,  Poison  Elder),  as  is  well  known,  severely 
affect  many  persons,  producing  a  kind  of  erysipelas.  Their  juice  is 
a  good  indelible  ink  for  marking  linen.  But  the  common  Sumachs 
(R.  typhina  and  R.  glabra)  are  innocuous ;  their  bark  or  leaves  are 
used  for  tanning,  and  their  sour  berries  (which  contain  bimalate  of 
lime)  for  acidulated  drinks.  The  oily  seeds  of  Pistacia  vera  (the 
Pistachio-nut)  are  edible ;  and  the  drupe  of  Mangifera  Indica 
(Mango)  is  one  of  the  most  grateful  of  tropical  fruits.  The  kernel 
of  the  Cashew-nut  (Anacardium  occidentale)  is  eatable ;  and  so  is 
the  enlarged  and  fleshy  peduncle  on  which  the  nut  rests  :  but  the 
coats  of  the  latter  are  filled  with  a  caustic  oil,  which  blisters  the 
skin  ;  while  from  the  bark  of  the  tree  a  bland  gum  exudes. 

792.  Ord.  BurseraceSB,  including  a  great  part  of  what  were  formerly 
called  Terebinthaceai,  consists  of  tropical  trees,  with  a  copious  resin- 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS. 


407 


ous  juice,  compound  leaves  usually  marked  with  pellucid  dots,  and 
small  flowers  ;  with  valvate  petals,  a  two-  to  five-celled  ovary,  and 
drupaceous  fruit.  Their  balsamic  juice,  which  flows  when  the  trunk 
is  wounded,  usually  hardens  into  a  resin.  The  Olibanum,  used  as  a 
fragrant  incense,  the  Balm  of  Gilead,  Balsam  of  Mecca,  Myrrh,  and 
the  Bdellium,  are  derived  from  Ai-abian  species  of  the  order  ;  the  East 
Indian  Gum  Elemi,  from  Canarium  commune;  Balsam  of  Acouchi, 
and  similar  substances,  from  various  American  trees  of  this  family. 

793.  Ord.  Aniyridaceni  consists  of  a  few  West  Indian  plants,  inter- 
mediate as  it  were  between  Burseraeere  and  Leguminosos,  and  dis- 
tinguished from  the  former  chiefly  by  their  simple  and  solitary  ovary. 
—  Very  probably  this  and  the  two  last  are  to  be  recombined. 


794.  Ord.  Titacese   (  Vine  Family).     Shrubby  plants,  climbing  by 
tendrils,    with    simple    or    compound   leaves,    the   upper   alternate. 

FIG.  767.  A  branch  of  the  Grape-Vine.  768.  A  flower ;  the  petals  separating  from  the 
base,  and  falling  off  together  without  expanding.  769.  A  flower  from  which  the  petals  hare 
fallen ;  the  lobes  of  the  disk  seen  alternate  with  the  stamens.  770.  Vertical  section  through 
the  ovary  and  the  base  of  the  flower :  a,  calyx,  the  limb  of  which  is  a  mere  rim  :  6,  petal, 
having  the  stamen,  c,  directly  before  it ;  and  the  lobes  of  the  disk  are  shown  between  this  and 
the  ovary.  771.  A  seed.  772.  Section  of  the  seed,  showing  the  thick  crustaceous  testa,  and 
the  albumen,  at  the  base  of  which  is  the  minute  embryo.    772'.  A  horizontal  plan  of  the  flower. 


408  ILLUSTRATIONS    OF    THE   NATURAL    ORDERS. 

Flowers  small,  often  polygamous  or  dioecious.  Calyx  Aery  small, 
filled  with  a  disk  ;  its  limb  short  or  obsolete.  Petals  4  or  5,  valvate 
in  aestivation,  sometimes  cohering  by  their  tips,  and  caducous.  Sta- 
mens as  many  as  the  petals  and  opposite  them  !  Ovary  two-celled, 
with  two  erect  ovules  in  each  cell.  Fruit  a  berry.  Seeds  with  a 
bony  testa,  and  a  small  embryo  in  hard  albumen.  —  Ex.  Vitis  (the 
Vine),  Ampelopsis  (the  Virginia  Creeper).  The  fruit  of  the  Vine 
is  the  only  important  product  of  the  order.  The  acid  of  the  grape, 
which  also  pervades  the  young  shoots  and  leaves,  is  chiefly  the  tar- 
taric. Grape-sugar  is  very  distinct  from  cane-sugar,  and  the  only 
kind  that  can  long  exist  in  connection  with  acids. 

795.  Ortl.  RliamiiaceBB  {Buckthorn  Family).  Shrubs  or  trees,  often 
with  spinose  branches ;  the  leaves  mostly  alternate,  simple.  Flowers 
small.  Calyx  of  four  or  five  sepals,  united  at  the  base,  valvate  in 
aestivation.  Petals  four  or  five,  cucullate  or  convolute,  inserted  on 
the  throat  of  the  calyx,  sometimes  wanting.  Stamens  as  many  as 
the  petals,  inserted  with  and  opposite  them !  Ovary  sometimes 
coherent  with  the  tube  of  the  calyx,  and  more  or  less  immersed  in  a 
fleshy  disk,  with  a  single  erect  ovule  in  each  cell  (Fig.  435,  436). 
Seeds  not  arilled.  Embryo  straight,  large,  in  sparing  albumen.  — 
Ex.  Rhamnus  (Buckthorn)  is  the  type  of  the  order.  The  berries 
of  most  species  are  somewhat  nauseous  ;  but  those  of  Zizyphus  are 
edible.  Jujube  paste  is  prepared  from  those  of  Z.  Jujuba  and  Z. 
vulgaris  of  Asia.  Syrup  of  Buckthorn  and  the  pigment  called  Sap- 
green  are  prepared  from  the  fruit  of  Rhamnus  catharticus.  The 
herbage  and  bark  in  this  order  are  more  or  less  astringent  and 
bitter.  An  infusion  of  the  leaves  of  Ceanothus  Americanus  (thence 
called  New  Jersey  Tea)  has  been  used  as  a  substitute  for  tea,  and  a 
very  poor  one  it  is. 

79 G.  Ord.  Celastracese  {Spindle-tree  Family).  Shrubs  or  trees, 
with  alternate  or  opposite  simple  leaves.  Calyx  of  four  or  five 
sepals,  imbricated  in  aestivation.  Petals  as  many  as  the  sepals,  in- 
serted under  the  flat  expanded  disk  which  closely  surrounds  the 
ovary,  imbricated  in  aestivation.  Stamens  as  many  as  the  petals, 
and  alternate  with  them,  inserted  on  the  margin  or  upper  surface 
of  the  disk.  Ovary  free  from  the  calyx.  Fruit  a  capsule  or  berry, 
with  one  or  few  seeds  in  each  cell.  Seeds  usually  arilled,  albumi- 
nous, with  a  large  and  straight  embryo.  —  Ex.  Celastrus,  Euonymus 
(Burning  Bush,  Spindle-tree,  Strawberry-tree)  ;  all  somewhat  bitter 
and  acrid ;  but  of  little  economical  importance.     The  red  or  crim- 


EXOGENOUS    OR    DICOTYLEDONOUS    TLANTS. 


409 


son  capsules  and  bright  scarlet  arils  of  several  species  present  a 
striking  appearance  when  the  fruit  is  ripe. 

797.  Ol'd.  Malpigbiacerc  is  a  large  tropical  family  (with  one  or  two 
representatives  in  Texas),  of  trees,  shrubs,  and  twining  plants,  with 
opposite  entire  leaves,  unguiculate  petals,  and  solitary  seeds  with  a 
curved  embryo ;  differing  from  the  next  in  the  want  of  a  disk,  the 
more  symmetrical  flowers,  &c. 

798.  Ol'd.  SapilldaceSB  {Soapberry  Family).  Trees,  shrubs,  or  climb- 
ers with  tendrils,  rarely  herbs,  with  simple  or  compound  leaves,  and 
mostly  unsymmetrical  or  irregular  flowers  ;  the  sepals  and  petals 
imbricated  in  aestivation.  Stamens  5  to  10,  inserted  on  a  fleshy 
perigynous  or  hypogynous  disk.  Ovary  2-3-celled,  2-3-lobed,  with 
one  or  two  (in  Stapbylea  several)  ovules  in  each  cell ;  the  embryo 
(except  in  Stapbylea)  curved  or  convolute  and  without  albumen.  — 
Includes  a  variety  of  forms,  the  greater  part  of  which  may  be  ranged 
under  the  following  suboi'ders,  winch  have  been  taken  for  orders. 


799.  Subord.  Staphyleaceae  (Bladdemut  Family)  has  opposite  com- 
pound leaves  with  stipules  and  stipels,  regular  and  perfect  pentan- 


FIG.  773.  Flowering  branch  of  .Esculus  Pavia  (Red  Buckeye).  774.  A  flower.  775.  Flower 
with  the  calyx  and  two  of  the  petals  removed.  776.  A  ground-plan  of  the  flower,  showing 
that  its  parts  are  unsymmetrical.  777.  Vertical  section  of  an  ovary,  showing  two  of  the  cells 
with  a  pair  of  ovules  in  each,  one  ascending,  one  descending.  778.  Cross  section  of  an  ovary. 
779.  Cross-section  of  the  immature  fruit ;  only  one  fertile  seed ;  the  others  abortive.  780. 
The  dehiscent  fruit. 

35 


410 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


drous  flowers,  three  partly  united  pistils  with  several  ovules  in  each, 
and  large  bony  seeds,  with  a  straight  embryo  in  scanty  albumen.  — 
Ex.  Staphylea. 

800.  Sllboi'd.  SapindCEC  {Soapberry  Family  proper)  has  alternate,  or 
in  the  Horsechestnut  tribe  opposite  leaves,  without  stipules,  more  or 
less  unsymmetrical  or  irregular  and  polygamous  flowers,  exalbu- 
minous  seeds,  and  a  curved  embryo  with  thickened  cotyledons.  — 
Mostly  tropical,  except  the  Horsechestnut  and  Buckeyes  (^Esculus), 
which  have  been  deemed  a  separate  family  (Ilippocastanece).  Their 
very  large  and  fleshy  embryo  has  the  cotyledons  more  or  less  con- 
solidated (Fig.  629,  630).  The  seeds  of  the  Horsechestnut  are  nu- 
tritious, but  contain  an  intensely  bitter  principle  which  is  more  or 
less  noxious.  Those  of  JE.  Pavia  are  used  to  stupefy  fish.  The 
root,  according  to  Elliott,  is  employed  as  a  substitute  for  soap.  The 
fruit  of  Sapindus  is  used  for  the  same  purpose,  whence  the  name  of 
Soapberry. 

781  738  783 


801.  Sllbord.  AcerineSB  (Maple  Family)   has    opposite   (simple   or 
compound)  leaves  without  stipules,  a  2-lobed  and   2-winged  fruit 

FIG.  781.  A  branch  of  Acer  dasycarpuui  (the  White  Soft  Maple)  with  staminate  flowers. 
782.  A  separate,  enlarged,  staminate  flower.  783.  Branch  with  pistillate  flowers.  784.  A 
separate  fertile  flower.  785.  The  same,  enlarged,  with  the  calyx  cut  away.  786.  A  cluster 
showing  the  fruiting  ovaries  expanding  into  wings  (reduced  in  size).  787.  Kipe  fruit ;  one  of 
the  samaras  cut  open  to  show  the  seed.     788.  A  leaf. 


EXOGENOUS    OR    DICOTYLEDONOUS    TLANTS. 


411 


forming  two  samaras,  and  an  embryo  with  long  and  thin,  variously 
curved  or  coiled  cotyledons  (Fig.  103  - 105)  ;  otherwise  nearly  as 
in  the  true  Sapindaceae.  —  Ex.  Acer,  the  Maple  ;  useful  timber-trees 
of  northern  temperate  regions.  Sugar  is  yielded  by  the  vernal  sap 
of  Acer  saccharinum,  and  in  less  quantity  by  all  the  species. 

802.  Ord.  TolygalacefE.  Herbs  or  shrubby  plants,  with  simple 
entire  leaves,  destitute  of  stipules.  Flowers  perfect,  unsymmetrical, 
and  irregular,  somewhat  papilionaceous  in  appearance,  but  of  wide- 
ly different  structure.  Calyx  of  five  irregular  sepals  ;  the  odd  one 
superior,  the  two  inner  (wings)  larger,  and  usually  petaloid.  Petals 
usually  three,  inserted  on  the  receptacle,  more  or  less  united ;  the 
anterior  (keel)  larger  than  the  rest.  Stamens  six  to  eight,  combined 
in  a  tube,  which  is  split  on  the  upper  side,  and  united  below  with 
the  claws  of  the  petals :  anthers  innate,  mostly  one-celled,  opening 
by  a  pore  at  the  apex.  Ovary  compound,  two-celled,  with  a  single 
suspended   ovule   in   each   cell :    style   curved  and   often   hooded. 


Capsule  flattened.  Seeds  usually  with  a  caruncle.  Embryo  straight, 
large,  in  fleshy,  thin  albumen.  —  Ex.  Polygala  is  the  principal  genus 
of  the  order.     The  plants  yield  a  bitter  principle  with  some  acrid 

FIG.  789.  Polygala  paucifolia.  790.  A  flower,  enlarged.  791.  The  calyx  displayed.  792. 
The  corolla  and  stamineal  tube  laid  open.  793.  The  pistil  and  the  free  portion  of  the  stamens. 
794.  Vertical  section  of  the  ovary.  795.  Vertical  section  of  the  seed,  showing  the  large  embryo 
and  scanty  albumen. 


412  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

extractive  matter.  Polygala  Senega  (Seneca  Snakeroot)  is  the 
most  important  medicinal  plant  of  the  family.  Other  species  are 
employed  medicinally  in  Brazil,  Peru,  Nepaul,  &c. ;  where,  like 
our  own,  they  are  reputed  antidotes  to  the  bites  of  venomous 
reptiles. 

803.  Ord.  KrameriacCSB  {Rhatany  Family)  consists  of  the  genus 
Krameria  only,  which  has  ordinarily  been  annexed  to  the  Polyga- 
lacea?  ;  but  the  position  of  the  parts  of  the  flower  is  more  like  that 
of  the  Leguminosa?,  having  the  odd  sepal  inferior,  a  simple  unilocu- 
lar pistil,  and  an  exalbuminous  seed.  In  fact  it  is  technically  distin- 
guishable from  the  latter  chiefly  by  the  hypogynous  stamens  and  the 
want  of  stipules.  The  roots  contain  a  red  coloring  matter,  and  are 
astringent  without  bitterness.  Rhatany-root,  used  to  adulterate  port- 
wine,  and  as  an  ingredient  in  tooth-powders,  &c,  is  the  produce  of 
K.  triandra  of  Peru.  That  of  our  own  Southern  species  possesses 
the  same  properties. 


804.  Ord.  IcgliminoSEe  {Pulse  Family).     Herbs,  shrubs,  or  trees, 
with  alternate  and  usually  compound  leaves,  furnished  with  stipules. 

FIG.  796.  A  flowering  branch  of  Lathyrus  palustris,  var.  myrtifolius.  797.  The  corolla 
displayed  :  a,  the  vexillum  or  standard ;  i,  the  alae  or  wings  ;  c,  the  two  petals  of  the  carina 
or  keel.  798.  The  keel-petals  in  their  natural  situation.  799.  The  stamens  and  pistil,  en- 
larged ;  the  sheath  of  filaments  partly  turned  back. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


413 


Calyx  mostly  of  five  sepals,  more  or  less  united  ;  the  odd  sepal  in- 
ferior (Fig.  358).  Corolla  of  five  petals,  either  papilionaceous  or 
regular.  Stamens  perigynous,  or  sometimes  hypogynous.  Ovary 
single  and  simple.  Fruit  a  legume,  various  forms  of  which  are 
shown  in  Fig.  580,  581,  800-807.  Seeds  destitute  of  albumen,  or 
with  a  mere  vestige  of  it.  —  This  immense  family  is  divided  into 
three   principal   suborders  ;  viz. :  — 


805.  Subord.  PapilionaceOB  (Pulse  Family  proper),  which  is  charac- 
terized by  the  papilionaceous  corolla,  —  the  vexillum  always  exter- 
nal in  aestivation  (471,  Fig.  392),  —  ten  diadelphous  (Fig.  4G1), 
monadelphous  (Fig.  462),  or  rarely  distinct,  perigynous  stamens, 
and  the  radicle  bent  on  the  large  cotyledons.  Leaves  (rarely  sim- 
ple) only  once  compound ;  the  leaflets  very  rarely  toothed  or  lobed. 

806.  Subord.  CSBSalpineOB  (to  which  Cassia,  Cercis,  and  the  Honey- 
Locust  belong)  :  here  the  corolla  gradually  loses  its  papilionaceous 
character,  and  always  has  the  vexillum,  or  superior  petal,  covered 
by  the  lateral  ones  in  aestivation  ;  the  stamens  are  distinct,  and  the 
embryo  straight.     The  leaves  are  often  bipinnate. 

807.  Subord.  MimoseSB  (a  large  group,  to  which  the  Acacia  and  the 
Sensitive  Plant  belong)  has  a  perfectly  regular  calyx  and  corolla, 
the  latter  mostly  valvate  in  aestivation  and  hypogynous,  as  well  as 
the  stamens,  which  are  sometimes  definite,  but  often  very  numerous ; 
and  the  embryo  is  straight.     The  leaves  are  frequently  tripinnate. 

FIG.  800.  Open  legume  of  the  Pea.  801.  Loment  of  Desmodium.  802.  Loment  of  Mi- 
mosa :  b,  one  of  its  dehiscent  joints  which  has  fallen  away  from  the  persisting  border  or  frame 
(rcpluni),  seen  in  803.  804.  The  jointed  indehiscent  legume  of  Sophora.  805.  A  legume  of 
Astragalus,  cut  across  near  the  summit,  to  show  how  it  becomes  partly  or  entirely  two-celled 
by  the  introflexion  of  the  dorsal  suture.  806.  Similar  view  of  a  legume  of  Phaca,  where  the 
ventral  suture  is  somewhat  introflexed.  80".  A  legume  of  Medicago  scutellata,  spirally  coiled 
into  a  globular  figure. 

35* 


414  ILLUSTRATIONS    OF   THE   NATURAL    ORDERS. 

808.  Papilionaceae  are  found  in  every  part  of  the  world :  Coesal- 
pineas  and  Mimoseae  are  confined  to  the  tropical  and  warmer  tem- 
perate regions.  —  A  full  account  of  the  useful  plants  and  products 
of  this  large  order  would  require  a  separate  volume.     Many,  such 
as  Clover,  Lucerne  (Medicago  sativa),  &c,  are  extensively  culti- 
vated for  fodder ;  Peas  and  Beans,  for  pulse.     The  roots  of  the 
Licorice   (Glycirrhiza   glabra  of   Southern   Europe)   abound   in  a 
sweet  mucilaginous  juice,  from  which  the  pectoral  extract  of  this 
name  is  prepared.     The  sweet  pulp  of  the  pods  of  Ceratonia  Siliqua 
(Carob-tree  of  the  South  of  Europe,  &c),  like  that  of  the  Honey- 
Locust  (Gleditschia),  &c,  is  edible.     The  laxative  pulp  of  Cathar- 
tocarpus  Fistula,  and  of  the  Tamarind,  is  well  known  ;  the  latter  is 
acidulated  with  malic,  and  a  little  tartaric  and  citric  acid.  — A  pecu- 
liar volatile  principle  (called  Coumarin)  gives  its  vanilla-like  fra- 
grance to  the  well-known  Tonka-bean,  and  to  the  Melilotus,  or  Sweet 
Clover.     The  flowers  and  seeds   of  the  latter  and  of  Trigonella 
cajrulea  give  the  peculiar  odor  to  Scheipzeiger  cheese.  —  Astringents 
and  tonics  are  also  yielded  by  this  order :  such  as  the  African  Ptero- 
carpus  erinaceus,  the  hardened  red  juice  of  which  is  Gum  Kino  ; 
that  of  P.  Draco,  of  Carthagena,  &c,  is  Dragon's  Blood.     The  bark 
of  most  Acacias  and  Mimosas  contains  a  very  large  quantity  of  tan- 
nin, and  is  likely  to  prove  of  great  importance  in  tanning.     The 
valuable  astringent  called  Catechu  is  obtained  by  boiling  and  evap- 
orating the  heart-wood  of  the  Indian  Acacia  Catechu.  —  Legumi- 
nosa3  yield  the  most  important  coloring  matters :  such  as  the  Brazil- 
wood, the  Logivood  of  Campeachy  (the  peculiar  coloring  principle 
of  which  is  called  Hcematin),  and  the  Red  Sandal-wood  of  Ceylon. 
Indigo  is  prepared  from  the  fermented  juice  of  the  Indigofera  tinc- 
toria  (a  native  of  India),  and  other  species  of  the  genus.     This 
substance  is  highly  azotized,  and  is  a  violent  poison.  —  To  the  same 
order  we  are  indebted  for  valuable  resins  and  balsams  ;  such  as  the 
Mexican  Copal,  Balsam  of  Copaiva  of  the  West  Indies,  Para,  and 
Brazil,  the  bitter  and  fragrant  Balsam  of  Peru,  and  the  sweet,  fra- 
grant, and  stimulant  Balsam  of  Tolu.  —  It  also  furnishes  the  most 
useful  gums ;  of  which  we  need  only  mention   Gum   Tragacanth, 
derived  from  Astragalus  verus  of  Persia,  &c. ;  and   Gum  Arabic, 
the  produce    of  certain  African    species  of  Acacia.      The  best  is 
said  to  be  obtained  from  Acacia  vera,  while  Gum  Senegal  is  yielded 
by  A.  Verek,  and  some  other  species.     Algarobia  dulcis,  the  Mes- 
quite  of  Texas  and  Mexico,  yields  a  similar  gum.     The  Senna  of 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS.  415 

commerce  consists  of  the  leaves  of  several  species  of  Cassia,  of 
Egypt  and  Arabia.  C.  Marilandica  of  this  country  is  a  succedane- 
um  for  the  officinal  article.  —  More  acrid,  or  even  poisonous  prop- 
erties, are  often  met  with  in  the  order.  The  roots  of  Baptisia 
tinctoria  (called  Wild  Indigo,  because  it  is  said  to  yield  a  little  of 
that  substance),  of  the  Broom,  and  of  the  Dyers'  "Weed  (Genista 
tinctoria,  used  for  dyeing  yellow),  possess  such  qualities  ;  while  the 
seeds  of  Laburnum,  &c.  are  even  narcotico-acrid  poisons.  The 
branches  and  leaves  of  Tephrosia,  and  the  bark  of  the  root  of 
Piscidia  Erythrina  (Jamaica  Dogwood,  which  is  also  found  in  South- 
ern Florida),  are  commonly  used  in  the  West  Indies  for  stupefying 
fish.  Coivitch  is  the  stinging  hairs  of  the  pods  of  species  of  Mu- 
cuna.  —  Among  the  numerous  valuable  timber-trees,  our  own  Locust 
(Bobinia  Pseudacacia)  must  be  mentioned ;  and  also  the  Bosewood 
of  commerce,  the  produce  of  some  Brazilian  Cresalpinierc.  Few 
orders  furnish  so  many  plants  cultivated  for  ornament. 

809.  Ord.  Rosacea)  (Rose  Family).  Trees,  shrubs,  or  herbs,  with 
alternate  leaves,  usually  furnished  with  stipules.  Flowers  regular. 
—  Calyx  of  five  (rarely  three  or  four)  more  or  less  united  sepals, 
and  often  with  as  many  bracts.  Petals  as  many  as  the  sepals 
(rarely  none),  mostly  imbricated  in  aestivation,  perigynous.  Sta- 
mens indefinite,  or  sometimes  few,  distinct.  Ovaries  with  solitary 
or  few  ovules :  styles  often  lateral.  Albumen  none.  Embryo 
straight,  with  broad  and  flat  or  plano-convex  cotyledons  (Fig.  108- 
111). — This  important  order  is  divided  into  four  suborders;  viz.:  — 

810.  Suhortl.  ClirysobalanCflB  (Cocoa-plum  Family).  This  is  now 
generally  taken  as  an  independent  order,  intermediate  between 
Leguminosa}  and  Bosacere.  Ovary  solitary,  free  from  the  calyx,  or 
else  cohering  with  it  at  the  base  on  one  side  only,  containing  two 
erect  ovules  :  style  arising  from  the  apparent  base.  Fruit  a  drupe. 
Trees  or  shrubs.  —  Ex.  Chrysobalanus  ;  some  species  of  which  pro- 
duce an  edible  fruit. 

811.  Subord.  Amygdalcce  (Almond  or  Plum  Family).  Ovary  soli- 
tary, free  from  the  deciduous  calyx,  with  two  suspended  ovules,  and 
a  terminal  style.  Fruit  a  drupe  (Fig.  5G2).  Trees  or  shrubs. — 
Ex.  Amygdalus  (the  Almond,  Peach),  Prunus  (the  Plum),  &c. 

812.  Subord.  Rosacea)  proper.  Ovaries  several,  numerous,  or  rarely 
solitary,  free  from  the  calyx  (which  is  often  bractcolate,  as  if 
double),  but  sometimes  enclosed  in  its  persistent  tube,  in  fruit  becom- 
ing either  follicles  or  achenia.     Styles  terminal  or  lateral.     Herbs  or 


416 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


shrubs.  —  The  three  tribes  of  this  suborder  are :  —  Tribe  1.  Spireme. 
where  the  fruit  is  a  follicle.  Ex.  Spiraea  and  Gillenia.  Tribe  2. 
Dryade^e,  where  the  fruits  are  achenia,  or  sometimes  little  drupes, 
and  when  numerous  crowded  on  an  enlarged  torus  (Fig.  558,  559, 
564,  565).  Ex.  Dryas,  Agrimonia,  Potentilla,  Fragaria  (Strawber- 
ry), Rubus  (Raspberry  and  Blackberry).  Tribe  3.  Roseje,  where 
numerous  achenia  cover  the  hollow  torus  which  lines  the  urn-shaped 
calyx-tube ;  and  the  latter,  being  contracted  at  the  mouth,  and  be- 
coming fleshy  or  berry-like,  forms  a  kind  of  false  pericarp  ;  as  in  the 
Rose  (Fig.  429,  808). 

813.  Sllbord.  PomefB  {Pear  Family).  Ovaries  two  to  five,  or  rare- 
ly solitary,  cohering  with  each  other  and  with  the  thickened  and 
fleshy  or  pulpy  calyx-tube ;  each  with  one  or  two  (in  the  Quince 
several)  ascending  seeds.  Trees  or  shrubs.  —  Ex.  Crataegus  (the 
Thorn),  Cydonia  (the  Quince),  Pyrus  (the  Apple,  Pear,  &c). 


814.  This  important  order  is  diffused  through  almost  every  part 
of  the  world ;  but  cliiefly  abounds  in  temperate  climates,  where  it 
furnishes  the  most  important  fruits.  It  is  destitute  of  unwholesome 
qualities,  with  one  or  two  exceptions,  viz. :  —  The  bark,  leaves,  and 
kernel  of  Amygdalese  contain  prussic  acid,  or  something  of  similar 
odor  and  analogous  properties ;  as  is  exemplified  by  the  Cherry-Laurel 

FIG.  808.  Vertical  section  of  an  unexpanded  Rose,  showing  the  attachment  of  the  carpels 
to  the  lining  of  the  calyx-tube,  and  of  the  stamens  and  petals  to  its  summit  or  edge.  809. 
Vertical  section  of  the  fruit  of  the  Quince,  exhibiting  the  carpels  invested  by  the  thickened 
calyx  which  forms  the  edible  part  of  the  fruit ;  one  of  the  ovaries  laid  open  to  show  the  seeds. 
810.  A  magnified  seed  ;  the  rhaphe  and  chalaza  conspicuous.  811.  The  embryo.  812.  Cross- 
section  of  an  apple.    813.  Flower,  &c.  of  the  American  Crab-apple  (Pyrus  coronariu). 


EXOGENOUS    OK    DICOTYLEDONOUS    PLANTS. 


417 


of  the  Old  World,  from  which  the  poisonous  Laurel-water  and  the 
virulent  Oil  of  Laurel  are  obtained.  Our  Southern  species,  Primus 
(Laurocerasus)  Caroliniana,  poisons  cattle  which  eat  its  foliage. 
The  root  of  Gillenia  (Bowman's  Root,  Indian  Physic)  is  emetic  in 
large  doses,  in  small  doses  it  acts  as  a  tonic.  The  bark  and  root  in 
all  are  astringent.  The  bark  of  Amygdaleae  also  exudes  gum. 
That  of  the  Wild  Black  Cherry  is  febrifugal ;  and  the  timber  is 
useful  in  cabinet-work.  Sweet  and  bitter  almonds  are  the  seeds  of 
varieties  of  Amygdalus  communis :  the  oil  of  the  former  resembles 
olive-oil ;  that  of  the  latter  is  poisonous.  Of  the  Peach,  Apricot, 
Nectarine,  Plum,  and  Cherry,  it  is  unnecessary  to  speak.  The 
strawberry,  raspberry,  and  blackberry  are  the  principal  fruits  of  the 
proper  Rosacea3.  The  leaves  of  Rosa  centifolia  are  more  commonly 
distilled  for  Rose-water :  and  Attar  of  Roses  is  obtained  from  R. 
Damascena,  &c.  —  Pomaceous  fruits,  such  as  the  apple,  pear,  quince, 
services,  medlar,  &c,  yield  to  none  in  importance :  their  acid  is 
usually  the  malic. 


814  821  819 

815.  Ord.  CalycanthaceSB.     A  small  group  of  shrubs,  between  the 

FIG.  814.  Flowers  of  Calycanthus  floridus.  815.  Vertical  section  of  a  flower,  showing  the 
hollow  receptacle,  &c. ;  the  floral  envelopes  cut  away.  816.  A  stamen,  seen  from  without. 
817.  A  pistil.  818.  Section  of  the  ovary,  showing  the  two  ascending  ovules.  819.  The  closed 
pod-shaped  receptacle  in  fruit.  820.  A  vertical  section  of  an  achenium,  showing  the  embryo 
of  the  seed.     821.  Cross-section  of  an  embryo,  showing  the  strongly  convolute  cotyledons. 


418  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

last  order  and  the  next,  distinguished  from  Rosacea?  hy  their  oppo- 
site leaves  without  stipules,  and  their  convolute  cotyledons  :  the 
ovaries  are  enclosed  in  a  fleshy  calyx-tube  as  in  a  rose-hip.  —  It 
comprises  only  two  genera ;  viz.  Calycanthus  (Carolina  Allspice, 
Sweet-scented  Shrub,  &c),  and  Chimonanthus,  of  Japan.  They  are 
cultivated  for  their  fragrant  flowers  The  bark  and  foliage  exhale 
a  slight  camphoric  odor ;  and  the  flowers  give  a  fragrance  like  that 
of  strawberries. 

81G.  Ol'd.  MyrtaceS  {Myrtle  Family).  Aromatic  trees  or  shrubs, 
with  opposite  and  simple  entire  leaves,  which  are  punctate  with 
pellucid  dots,  and  often  furnished  with  a  vein  running  parallel  with 
and  close  to  the  margin,  without  stipules  ;  the  calyx-tube  adherent 
to  the  ovary ;  many  stamens ;  and  seeds  without  albumen.  —  Ex. 
Myrtus,  the  Myrtle,  is  the  most  familiar  representative  of  this 
beautiful  tropical  and  subtropical  order.  The  species  abound  in  a 
pungent  and  aromatic  volatile  oil,  and  an  astringent  principle. 
Cloves  are  the  dried  flower-buds  of  Caryophyllus  aromaticus.  Pi- 
mento (Allspice)  is  the  dried  fruit  of  Eugenia  Pimenta.  Cajeput 
oil,  a  powerful  sudorific,  is  distilled  from  the  leaves  and  fruit  of  a 
Melaleuca  of  the  Moluccas.  Australian  species  of  Eucalyptus  yield 
a  large  quantity  of  tannin.  The  aromatic  fruits  of  many  species, 
ulled  with  sugar  and  mucilage,  and  acidulated  with  a  free  acid,  are 
highly  prized ;  such,  for  instance,  as  the  Pomegranate,  the  Guava, 
Rose-Apple,  &c. 

817.  Ord.  Melastomacea).  Trees,  shrubs,  or  herbs,  with  opposite 
ribbed  leaves,  and  showy  flowers,  with  as  many  or  twice  as  many 
stamens  as  petals ;  the  anthers  mostly  appendaged  and  opening  by 
pores,  inflexed  in  aestivation :  further  distinguished  from  Myrtaceae 
by  the  leaves  not  being  dotted ;  and  from  Lythraceae  by  the  adna- 
tion  of  the  calyx-tube  (by  its  nerves  at  least)  with  the  ovary.  — Ex. 
The  beautiful  species  of  Rhexia  represent  this  otherwise  tropical 
order  in  the  United  States.  The  berries  of  Melastoma  are  eatable, 
and  tinge  the  lips  black  (like  Avhortleberries)  ;  whence  the  generic 
name. 

818.  Ol'd.  LytliracCtE  {Loosestrife  Family)  is  distinguished  among 
these  perigynous  orders,  with  exalbuminous  seeds,  by  its  tubular 
calyx  enclosing  the  two  -  four-celled  ovary,  but  entirely  free  from  it. 
The  styles  are  perfectly  united  into  one :  the  fruit  is  a  thin  capsule. 
The  stamens  are  inserted  on  the  tube  of  the  calyx  below  the  petals. 
—  Ex.  Lythrum.     Chiefly  tropical,  of  little  economical  use. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


419 


819.  Ord.  RllizophoracCiC  {Mangrove  Family)  consists  of  a  few 
tropical  trees  (extending  into  Florida  and  Louisiana),  growing  in 
maritime  swamps,  where  they  root  in  the  mud,  and  form  thickets 
on  the  verge  of  the  ocean.  The  ovary  is  often  partly  free  from  the 
calyx,  two-celled,  with  two  pendulous  ovules  in  each  cell.  These 
plants  are  remarkable  for  their  opposite  leaves,  with  interpetiolar 
stipules,  and  for  the  germination  of  the  embryo  while  within  the 
pericarp.  —  Ex.  Rhizophora,  the  Mangrove  (Fig.  141).  The  as- 
tringent bark  has  been  used  as  a  febrifuge,  and  for  tanning. 

820.  Ord.  Coillbl'CtacCie  consists  of  tropical  trees  or  shrubs  (which 
have  one  or  two  representatives  in  Southern  Florida),  often  apeta- 
lous,  but  with  slender  colored  stamens  ;  distinguishable  from  any  of 
the  preceding  orders  of  this  group  by  their  one-celled  ovary,  with 
several  suspended  ovules,  but  only  a  solitary  seed,  and  convolute 
cotyledons.  —  Ex.  Combretum. 

821.  Ord.  OliagracCiE  {Evening-Primrose  Family).  Herbs,  or  rare- 
ly shrubby  plants,  with  alternate  or  opposite  leaves,  not  dotted  nor 


furnished  with  stipules.     Flowers  usually  tetramerous.     Calyx  ad- 
herent to  the  ovary,  and  usually  produced  beyond  it  into  a  tube. 


FIG.  822.  Flower  of  (Enothera  fruticosa.  823.  The  same,  with  the  petals  removed.  824. 
Magnified  grains  of  pollen,  with  some  of  the  intermixed  cellular  threads.  825.  Cross-section 
of  the  four-lobed  and  four-celled  capsule. 

FIG.  826.  Hippuris  vulgaris  (suborder  Halorageae).  827.  Magnified  flower,  with  the  sub- 
tending leaf.    828.  Vertical  section  of  the  ovary.     829.  Vertical  section  of  the  fruit  and  seed. 


420 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


Petals  usually  four  (rarely  three  or  six,  occasionally  absent),  and  the 
stamens  as  many,  or  twice  as  many,  inserted  into  the  throat  of  the 
calyx.  Ovary  commonly  four-celled  :  styles  united.  Fruit  mostly 
capsular.  —  Ex.  Chiefly  an  American  order  ;  many  are  ornamental 
in  cultivation.  Fuchsia,  remarkable  for  its  colored  calyx  and  ber- 
ried fruit ;  Oenothera  (Evening  Primrose)  ;  Epilobium,  where  the 
seeds  bear  a  coma ;  Ludwigia,  which  is  sometimes  apetalous  ;  and 
Circasa,  where  the  lobes  of  the  calyx,  petals,  stamens,  cells  of  the 
ovary,  and  the  seeds,  are  reduced  to  two ;  showing  a  connection  with 
the  appended 

822.  Sllbord.  HalorageCD,  which  are  a  sort  of  reduced  aquatic  Ona- 
graceoB,  often  apetalous  :  the  solitary  seeds  commonly  famished  with 
albumen. — Ex.  Myriophyllum  (Water-Milfoil)  and  Hippuris  (Horse- 
tail), where  the  limb  of  the  calyx  is  almost  wanting ;  the  petals 
none  ;  the  stamens  reduced  to  a  single  one,  and  the  ovary  to  a  single 
cell,  with  a  solitary  seed. 


823.  Ord.  GroSSUlacefK  (  Gooseberry  Family  ).     Small  shrubs,  either 
spiny  or  prickly,  or  unarmed ;  with  alternate,  palmately  lobed  and 


FIG.  830.  The  cultivated  Gooseberry  ;  a  branch  in  flower.  831.  Branch  in  fruit.  832. 
The  calyx,  bearing  the  petals  and  stamens,  cut  away  from  the  summit  of  the  ovary  (833),  and 
laid  open.  83-1,  835.  Sections  of  the  unripe  fruit.  836.  Magnified  seed,  with  a  conspicuous 
rhaphe.  837.  Longitudinal  section  of  the  same,  showing  the  minute  embryo  at  the  extrem- 
ity of  the  albumen. 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


421 


veined  leaves,  usually  in  fascicles,  often  sprinkled  with  resinous  dots. 
Flowers  in  racemes  or  small  clusters.  Calyx-tube  adherent  to  the 
one-celled  ovary,  and  more  or  less  produced  beyond  it,  five-lobed, 
sometimes  colored.  Petals  (small)  and  stamens  five,  inserted  on 
the  calyx.  Ovary  with  two  parietal  placenta? :  styles  more  or  less 
united.  Fruit  a  many-seeded  berry.  Embryo  minute,  in  hard 
albumen. — Ex.  Ribes  (Gooseberry  and  Currant).  Never  unwhole- 
some :  the  fruit  usually  esculent,  containing  a  mucilaginous  and  sac- 
charine pulp,  with  more  or  less  malic  or  citric  acid.  Two  or  three 
red-flowered  species  of  Oregon  and  California,  and  the  Yellow  or 
Missouri  Currant,  are  ornamental  in  cultivation. 

824.  Ol'd.  CactacefE  {Cactus  Family).  Succulent  shrubby  plants, 
peculiar  in  habit,  with  spinous  buds,  usually  leafless :  the  stems 
either  globular  and  many- 
angled,  columnar  with  several 
angles,  or  flattened  and  joint- 
ed. Flowers  usually  large 
and  showy.  Calyx  of  sev- 
eral or  numerous  sepals,  im- 
bricated, coherent  with  and 
crowning  the  one-celled  ova- 
ry, or  covering  its  whole  sur- 
face ;  the  inner  usually  con- 
founded with  the  indefinite 
petals.  Stamens  indefinite, 
with  long  filaments,  cohering 
with  the  base  of  the  petals. 
Styles  united :  stigmas  and  parietal  placenta?  several.  Fruit  a 
berry.  Seeds  numerous,  with  a  curved  or  fleshy  and  rounded  em- 
bryo, and  little  or  no  albumen.  —  All  American,  the  greater  part 
Mexican  or  on  the  borders  of  Mexico.  The  common  Opuntia 
(Prickly  Pear)  extends  north  to  New  England :  its  mucilaginous 
fruit  is  eatable.  So  is  the  sweet  red  pulp  of  the  huge  Cereus  gigan- 
teus  of  Sonora  and  South  California,  which  forms  a  singular  tree, 
forty  or  fifty  feet  high.  Cereus  grandiflorus  is  the  magnificent 
Night-blooming  Cereus. 

825.  Ol'd.  LoasaceSE.  Herbs  usually  clothed  with  rigid  or  stinging 
hairs ;  leaves  opposite  or  alternate,  without  stipules ;  the  flowers 
showy.     Calyx-tube   adherent  to  the  one-celled  ovary;    the  limb 

FIG.  838.    Flower  of  Mamillaria  caespitosa,  of  the  Upper  Missouri- 

36 


422  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

mo.-tly  five-parted.  Petals  as  many,  or  twice  as  many,  as  the  lobes 
of  the  calyx.  Stamens  perigynous,  indefinite,  and  in  several  parcels, 
or  sometimes  definite.  Style  single.  Ovary  with  three  to  five 
parietal  placentas.  Seeds  few  or  numerous,  albuminous.  —  Ex.  Lo- 
asa,  Mentzelia,  Cevallia ;  the  latter  with  solitary  seeds  and  no  albu- 
men. All  American,  and  in  the  United  States  nearly  confined  to 
the  regions  beyond  the  Mississippi.  The  bristles  of  Loasa  sting 
like  nettles. 

826.  Ol'd.  Tumeracese.  Herbs,  with  the  habit  of  Cistus  or  Heli- 
anthemum ;  the  alternate  leaves  without  stipules.  Flowers  solitary, 
showy.  Calyx  five-lobed  ;  the  five  petals  and  five  stamens  inserted 
on  its  throat.  Ovary  free  from  the  calyx,  one-celled,  with  three 
parietal  placenta?.  Styles  distinct,  commonly  branched  or  many- 
cleft  at  the  summit.  Fruit  a  three-valved  capsule.  Seeds  numer- 
ous (anatropous),  with  a  crustaceous  and  reticulated  testa,  and  a 
membranaceous  aril  on  one  side.  Embryo  in  fleshy  albumen. — Ex. 
Turnera,  of  which  there  is  one  species  in  Georgia. 

827.  Ol'd.  PassifloraceSB  (Passion-floiver  Family).  Herbs,  or 
somewhat  shrubby  plants,  climbing  by  tendrils ;  with  alternate, 
entire,  or  palmately-lobed  leaves,  mostly  with  stipules.  Flowers 
often  showy.  Calyx  mostly  of  five  sepals,  united  below,  free  from 
the  one-celled  ovary  ;  the  throat  bearing  five  petals  and  a  filament- 
ous crown.  Stamens  as  many  as  the  sepals,  monadelphous,  and  ad- 
hering to  the  stalk  of  the  ovary,  which  has  usually  three  club-shaped 
styles  or  stigmas,  and  as  many  parietal  placentas.  Fruit  fleshy  or 
berry-like.  Seeds  numerous,  with  a  brittle  sculptured  testa,  enclosed 
in  pulp.  Embryo  enclosed  in  a  thin  albumen.  —  Ex.  Passiflora  (the 
Passion-flower,  Granadilla)  :  nearly  all  natives  of  tropical  America. 
Two  species  are  found  as  far  north  as  Virginia  and  Ohio.  Many 
are  cultivated  for  their  singular  and  showy  flowers.  The  acidulous 
refrigerant  pulp  of  Passiflora  quadrangularis  (the  Granadilla),  P. 
edulis,  and  others,  is  eaten  in  the  West  Indies,  &c.  But  the  roots 
are  emetic,  narcotic,  and  poisonous. 

828.  Ol'd.  Papayaces  comprises  merely  a  small  genus  of  tropical 
dioecious  trees,  of  peculiar  character :  the  principal  one  is  the  Pa- 
paw-tree  (Carica  Papaya)  of  tropical  America,  which  has  been  in- 
troduced into  East  Florida.  The  fruit,  when  cooked,  is  eatable ; 
but  the  juice  of  the  unripe  fruit,  as  well  as  of  other  parts  of  the  plant, 
is  a  powerful  vermifuge.  The  juice  contains  so  much  fibrine  that  it 
has  an  extraordinary  resemblance  to  animal  matter :  meat  washed 


EXOGENOUS    OR    DICOTYLEDONOUS    TLANTS.  423 

in  water  impregnated  with  this  juice  is  rendered  tender :  even  the 
exhalations  from  the  tree  are  said  to  produce  the  same  effect  upon 
meat  suspended  among  the  leaves. 

829.  Ol'd.  CllCUrMtacefE  {Gourd  Family).  Tender  or  succulent 
herbs,  climbing  by  tendrils  ;  with  alternate,  palmately  veined  or 
lobed,  rough  leaves,  and  monoecious  or  dioecious  flowers.  Calyx  of 
four  or  five  (rarely  six)  sepals,  united  into  a  tube,  and  in  the  fertile 
flowers  adherent  to  the  ovary.  Petals  as  many  as  the  sepals,  com- 
monly more  or  less  united  into  a  monopetalous  corolla,  which  co- 
heres with  the  calyx.  Stamens  five  or  three,  or  rather  two  and  a 
half,  i.  e.  two  with  two-celled  anthers,  and  one  with  a  one-celled  an- 
ther, inserted  into  the  base  of  the  corolla  or  calyx,  either  distinct  or 
variously  united  by  their  filaments,  and  long,  sinuous  or  contorted 
anthers  (Fig.  465  —  467).  Ovary  one-  to  five-celled;  the  thick  and 
fleshy  placenta?  often  filling  the  cells,  or  diverging  before  or  after 
reaching  the  axis,  and  carried  back  so  as  to  reach  the  walls  of  the 
pericarp,  sometimes  manifestly  parietal ;  the  dissepiments  often  dis- 
appearing during  its  growth,  sometimes  only  one-ovuled  from  the  top  : 
stigmas  thick,  dilated  or  fringed.  Fruit  (pepo,  Fig.  560)  usually 
fleshy,  with  a  hard  rind,  sometimes  membranous.  Seeds  mostly  flat, 
with  no  albumen.  Embryo  straight:  cotyledons  foliaccous.  —  Ex. 
The  Pumpkin  and  Squash  (Cucurbita),  Gourd,  Cucumber,  and 
Melon.  "When  the  acrid  principle  wrhich  prevails  throughout  the 
order  is  greatly  diffused,  the  fruits  are  eatable,  and  sometimes  deli- 
cious :  when  concentrated,  as  in  the  Bottle  Gourd,  Bryony,  &c,  they 
are  dangerous  or  actively  poisonous.  The  officinal  Colocynth,  the 
resinoid  and  bitter  pulp  of  the  fruit  of  Cucumis  Colocynthis,  is  very 
acrid  and  poisonous  ;  and  Elaterium,  obtained  from  the  juice  of  the 
Squirting  Cucumber,  is  still  more  violent  in  its  effects.  The  seeds 
of  all  are  harmless. 

830.  Ord.  CrassulaceSB  (Stonecrop  Family).  Herbs,  or  slightly 
shrubby  plants,  mostly  fleshy  or  succulent ;  remarkable  for  the  com- 
plete symmetry  and  regularity  of  their  flowers  (449,  Fig.  359  -  365). 
Calyx  of  three  to  twenty  sepals,  more  or  less  united  at  the  base, 
free  from  the  ovaries,  persistent.  Petals  as  many  as  the  sepals, 
rarely  combined  into  a  monopetalous  corolla.  Stamens  as  many  or 
twice  as  many  as  the  sepals,  more  or  less  perigynous.  Pistils  always 
as  many  as  the  sepals,  distinct,  or  rarely  (in  Penthorum  and  Dia- 
morpha)  partly  united :  ovaries  becoming  follicles  in  fruit,  several- 
seeded.     Embryo  straight,  in  thin  albumen.  —  Ex.  Sedum  (Stone- 


424 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


crop,  Orpine,  Live-for-ever),  Crassula,  Sempervivum  (Houseleek), 
&c.  They  mostly  grow  in  arid  places,  and  are  of  no  economical  im- 
portance. 

831.  Ord.  SaxifragacefC  {Saxifrage  Family).  Herbs  or  shrubs, 
with  alternate  or  opposite  leaves.  Calyx  of  four  or  five  more  or 
less  united  sepals,  either  free  from  or  more  or  less  adherent  to 
the  ovary,  persistent.  Petals  as  many  as  the  sepals,  rarely  want- 
ing. Stamens  as  many,  or  commonly  twice  as  many,  as  the  pistils 
or  sepals,  or  rarely  indefinitely  numerous,  perigynous.  Ovaries 
mostly  two  (sometimes  three  or  four),  usually  united  below  and 
distinct  above,  sometimes  completely  united  and  even  the  styles  also. 
Seeds  numerous,  with  a  straight  embryo  in  fleshy  albumen.  The 
order,  taken  in  the  largest  sense,  includes  four  tribes,  as  they  should 
probably  be  called,  rather  than  suborders,  which  some  botanists  regard 


even  as  distinct  orders,  viz. :  The  Saxifrages,  or  true  Saxifrage 
Family,  which  are  herbs,  with  no  manifest  stipules,  except  the  wings 
or  appendages  at  the  base  of  the  petiole  or  radical  leaves.     Ex.  Sax- 


FIO.  839.  Sullivantia  Ohionis.  840.  Flower  with  the  calyx  laid  open,  somewhat  enlarged. 
841.  Fruit  surrounded  by  the  persistent  calyx  and  withered  petals,  enlarged.  842.  Section  of 
the  lower  part  of  the  capsule,  magnified  ;  showing  the  central  placenta  covered  with  the  as- 
cending seeds.  843.  A  magnified  seed,  with  its  cellular,  wing-like  testa.  844.  Section  of  the 
nucleus,  showing  the  embryo  in  the  midst  of  albumen. 


EXOGENOUS    OK   DICOTYLEDONOUS   PLANTS-  425 

ifra^a,  Mitella,  &c.  Roots  somewhat  astringent,  in  Heuehera  so  much 
so  that  II.  Americana  is  called  Alum-root.  Hydrangieje  :  shrubs, 
with  simple  opposite  leaves  and  no  stipules.  Ex.  Hydrangea  and 
Philadelphia,  the  latter  polyandrous.  Bauere^e  :  Australian 
shrubs,  with  opposite  and  compound  sessile  leaves  and  no  stipules. 
Cunonieje  :  woody  plants,  with  opposite  simple  or  compound  leaves 
and  interpetiolar  stipules.  Escallonieje  :  woody  plants,  with 
alternate  simple  leaves  and  no  stipules.  Ex.  Escallonia,  of  South 
America,  Itea. 

832.  Ol'tl.  HamamelacCfe  {Witch- Hazel  Family).  Shrubs  or  small 
trees,  with  alternate  simple  leaves,  without  stipules.  Flowers  often 
polygamous.  Petals  valvate  in  aestivation.  Stamens  twice  as  many 
as  the  petals,  half  of  them  sterile  ;  or  numerous,  and  the  petals  none. 
Summit  of  the  two-celled  ovary  free  from  the  calyx,  a  single  ovule 
suspended  from  the  summit  of  each  cell :  styles  two,  distinct.  Cap- 
sule cartilaginous  or  bony.  Seeds  bony,  with  a  small  embryo  in 
hard  albumen.  —  Ex.  Hamamelis  (Witch-Hazel),  Fothergilla.  A 
small  order,  of  little  importance.  Hamamelis  is  remarkable  for 
flowering  late  in  autumn,  just  as  its  leaves  are  falling,  and  perfecting 
its  fruit  the  following  spring.  To  this  order  is  now  appended  the 
genus  Liquidambar,  or  Sweet-Gum,  which  has  been  taken  as  the 
type  of  a  distinct  order ;  but  it  is  rather  a  reduced  and  apetalous 
form  of  the  present  order.     It  may  stand  as  a  suborder,  viz. 

833.  Subord.  BalsamiflUfC  (Sweet-Gum  Family),  consisting  of  a 
few  trees,  with  alternate  palmately-lobed  leaves,  and  deciduous 
stipules  ;  the  monoecious  flowers  in  rounded  aments  or  heads,  desti- 
tute of  floral  envelopes ;  the  indurated  capsules  forming  a  head : 
they  are  two-beaked,  opening  between  the  beaks,  the  cells  ripening 
one  or  two  seeds,  although  the  ovules  are  numerous.  The  Sweet-gum 
is  so  called  from  a  fragrant  balsam  or  storax  which  it  exudes. 

834.  Ortl.  Ulllbellifera}  (Parsley  Fatnily).  Herbs,  with  hollow 
stems,  and  alternate,  dissected  leaves,  with  the  petioles  sheathing 
or  dilated  at  the  base.  Flowers  in  simple  or  mostly  compound  um- 
bels, which  are  occasionally  contracted  into  a  kind  of  head.  Calyx 
entirely  coherent  with  the  surface  of  the  dicarpellary  ovary;  its 
limb  reduced  to  a  mere  border,  or  to  five  small  teeth.  Petals  five, 
valvate  in  aestivation,  inserted,  with  the  five  stamens,  on  a  disk 
which  crowns  the  ovary;  their  points  inflexed.  Styles  two;  their 
bases  often  united  and  thickened,  forming  a  stylopodium.  Fruit 
dry,  a  ei-emocarp,  consisting  of  two  united  carpels,  at  maturity  sepa- 

3G* 


426 


ILLUSTRATIONS    OF    TIIE    NATURAL    ORDERS. 


rable  from  each  other,  and  often  from  a  slender  axis  (carpophore), 
into  two  aehenia,  or  mericarps :  the  face  by  which  these  cohere  re- 
ceives the  technical  name  of  commissure :  they  are  marked  with  a 
definite  number  of  ribs  (ji'ga),  which  are  sometimes  produced  into 
wings  :  the  intervening  spaces  (intervals),  as  well  as  the  commissure, 
sometimes  contain  canals  or  receptacles  of  volatile  oil,  called  vittce : 
these  are  the  principal  terms  peculiarly  employed  in  describing  the 
plants  of  this  difficult  family.  Embryo  minute.  Albumen  hard  or 
corneous.  —  Ex.    The   Carrot,    Parsnip,    Celery,    Caraway,  Anise, 


Coriander,  Poison  Hemlock,  &c.  are  common  representatives  of  this 
well-known  family.  Nearly  all  Umbelliferous  plants  are  furnished 
with  a  volatile  oil  or  balsam,  chiefly  accumulated  in  the  roots  and  in 
the  reservoirs  of  the  fruit,  upon  which  their  aromatic  and  carmina- 
tive properties  depend :  sometimes  it  is  small  in  quantity,  so  as 
merely  to  flavor  the  saccharine  roots,  which  are  used  for  food ;  as  in 
the  Carrot  and  Parsnip.  But  in  many  an  alkaloid  principle  exists, 
pervading  the  foliage,  stems,  and  roots,  especially  the  latter,  which  ren- 


FIG.  845.  Conium  maculatum  (Poison  Hemlock),  a  portion  of  the  spotted  stem,  with  a  leaf; 
and  an  umbel  -with  young  fruit.  846.  A  flowering  umbellet.  847.  A  flower,  enlarged.  848.  The 
fruit.  849.  Cross-section  of  the  same,  showing  the  involute  {campylospermous)  albumen  of  the 
two  seeds.  850.  Longitudinal  section  of  one  mericarp,  exhibiting  the  minute  embryo  near  the 
apex  of  the  albumen. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


42; 


ders  them  acrid-narcotic  poisons.  And,  finally,  many  species  of 
warm  regions  yield  odorous  gum-resins  (such  as  Galbanum,  Assa- 
fcetida,  &c),  which  have  active  stimulant  properties.  The  stems  of 
Celery  (Apium  graveolens),  which  are  acrid  and  poisonous  when 
the  plant  grows  wild  in  marshes,  &c,  are  rendered  innocent  by 


cultivation  in  dry  ground,  and  by  blanching.  Among  the  virulent 
acrid-narcotic  species,  the  most  famous  are  the  Hemlock  (Conium 
maculatum),  and  Cicuta  maculata  (Cowbane,  Water-Hemlock),  indi- 
genous to  this  country,  the  root  of  which  (like  that  of  the  C.  virosa 
of  Europe)  is  a  deadly  poison.  A  drachm  of  the  fresh  root  has 
killed  a  boy  in  less  than  two  hours. 

835.  Ord.  AraliacefE  {Ginseng  or  Ivy  Family)  scarcely  differs  from 


the  last  in  floral  structure,  except  that  the  ovary  is  mostly  composed 
of  more  than  two  carpels,  and  these  do  not  separate  Avhen  ripe,  but 

FIG.  851 .  Flower  of  Osmorrhiza  longistylis.  852.  Umfeel  of  the  same  in  fruit :  a,  the  invo- 
lucels.  853.  The  ripe  mericarps  separating  from  the  axis  or  carpophore.  854  Cross-section 
of  the  fruit  of  Angelica,  where  the  lateral  ribs  are  produced  into  wings  :  the  black  dots  repre- 
sent the  vittse,  as  they  appear  in  a  cross-section.  855.  One  of  the  mericarps  of  the  same,  show- 
ing the  inner  face,  or  commissure,  as  well  as  the  transverse  section,  with  two  of  the  vittse,  a. 

FIG.  856.  Flower  of  Aralia  nudicaulis  (Wild  Sarsaparilla) ;  a  vertical  section,  displaying 
two  of  the  cells  of  the  ovary.  857.  Cross-section  of  the  ovary.  858.  Longitudinal  section  of  a 
seed,  magnified,  showing  the  small  embryo  at  the  upper  end. 


428  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

become  drupes  or  berries  ;  and  the  albumen  is  not  hard  like  horn, 
but  only  fleshy.  —  Ex.  Aralia  (the  Spikenard,  the  "Wild  Sarsaparilla, 
Ginseng),  and  Hedera  (the  Ivy).  Their  properties  are  aromatic, 
stimulant,  somewhat  tonic,  and  alterative. 

836.  Ol'd.  CoMiacCEB  (  Cornel  or  Dogwood  Family).  Chiefly  trees  or 
shrubs  ;  with  the  leaves  almost  always  opposite,  destitute  of  stipules. 
Flowers  in  cymes,  sometimes  in  heads  surrounded  by  colored  involu- 
cres. Calyx  coherent  with  the  two-celled  ovary ;  the  very  small 
limb  four-toothed.  Petals  four,  valvate  in  aestivation.  Stamens 
four,  alternate  Avith  the  petals.  Styles  united  into  one.  Fruit  a 
two-celled  drupe.  Embryo  nearly  as  long  as  the  albumen ;  cotyle- 
dons broad  and  flat.  —  Ex.  Cornus,  the  Dogwood.  Chiefly  remark- 
able for  their  bitter  and  astringent  bark,  which  in  this  country  has 
been  substituted  for  Cinchona.  The  peculiar  principle  they  contain 
is  named  Cornine.  Cornus  Canadensis  (Fig.  321,  322)  is  a  low 
and  herbaceous  species.  —  A  reduced  form  of  this  order  occurs  in 
Nyssa  (the  Tupelo  or  Sour-Gum),  which  has  dioecious  or  polyga- 
mous flowers,  the  sterile  ones  at  least  apetalous,  the  fertile  ones  ap- 
pearing to  be  so  on  account  of  the  limb  of  the  adherent  calyx  being 
obsolete  ;  the  style  stigmatic  down  one  side  and  revolute  ;  the  ovary 
and  drupe  one-celled  and  one-seeded.  The  fruit  is  acid.  The  wood 
of  the  common  Sour  or  Black  Gum-tree,  or  Peperidge,  is  close- 
grained,  and  hard  to  split. 

Division  II.     Monopetalous  Exogenous  Plants. 

Floral  envelopes  consisting  of  both  calyx  and  corolla :  the  petals 
more  or  less  united  (corolla  gamopetalous) .  —  A  few  true  Ericaceae, 
with  all  the  Pyroleae  and  some  Monotropea*,  are  polypetalous  :  the 
Aquifoliaceae  are  nearly  so,  as  are  some  of  several  of  the  succeeding 
orders,  and  Fraxinus,  &c.  in  Oleacea?.  The  latter  genus  is  apeta- 
lous, and  so  are  one  or  two  genera  in  other  generally  Monopetalous 
orders. 

Conspectus  of  the  Orders. 

Group  1.  Ovary  coherent  with  the  calyx,  two-  to  several-celled,  with  one  or 
many  ovules  in  each  cell.  Seeds  albuminous,  with  a  small  embryo.  Sta- 
mens inserted  on  the  corolla.    Leaves  opposite. 

Stipules  wanting.  Caprifoliace^:. 

Stipules  interpetiolar  (or  in  one  group  the  leaves  whorled).  Rubiace^e. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS.  429 

Group  2.  Ovary  coherent  with  the  calyx,  one-celled  and  one-ovuled,  or  rarely 
3-cellcd  with  two  of  the  cells  empty,  and  the  third  one-ovuled.  Seed  with 
little  or  no  albumen.  Stamens  inserted  on  the  corolla.  Limb  of  the  ca- 
lyx a  mere  ring,  crown,  or  pappus,  or  none.     Stipules  none. 

Stamens  distinct.     Seed  suspended.     Leaves  opposite.  Stamens  3,  or  rarely  2. 

Flowers  often  irregular.  Valerianaceje. 

Stamens  4.  Flowers  regular,  in  an  involucrate  head.  DirsACE.E. 

Stamens  syngenesious.     Seed  erect.  Composite. 

Group  3.  Ovary  coherent  with  the  calyx,  with  two  or  more  cells  and  numer- 
ous ovules.  Seeds  albuminous.  Stamens  inserted  with  the  corolla  (epi- 
gynous)  :  anthers  not  opening  by  pores.     Juice  more  or  less  milky. 

Corolla  irregular.  Stamens  united  by  their  anthers  or  filaments.  Lobeliace;e. 
Corolla  regular.     Stamens  distinct.  Campanulace.e. 

Group  4.  Ovary  free  from  the  calyx,  or  sometimes  coherent  with  it,  with  two 
or  more  cells  and  few  or  many  ovules.  Seeds  albuminous.  Stamens  in- 
serted with  the  corolla,  or  rarely  somewhat  coherent  with  its  base,  as  many, 
or  twice  as  many,  as  its  lobes  :  anthers  mostly  opening  by  pores  or 
chinks.  Ericaceae. 

Group  5.  Ovary  free,  or  rarely  coherent  with  the  calyx,  several-celled,  with  a 
single  ovule  (or  at  least  a  single  seed)  in  each  cell.  Seeds  mostly  albu- 
minous. Stamens  definite,  as  many  as  the  lobes  of  the  (often  almost  poly- 
petalous)  corolla  and  alternate  with  them,  or  two  to  four  times  as  many : 
anthers  not  opening  by  pores.  —  Trees  or  shrubs. 

Stamens  as  many  as  the  lobes  of  the  corolla :  no  sterile  ones.  Aquifoliace^e. 
Stamens  more  numerous  than  the  lobes  of  the  corolla,  and  all  fertile. 

Flowers  polygamous  :  calyx  free.  EBENACEiE. 

Flowers  perfect :  calyx  more  or  less  adnate.  Styracace.*:. 

Stamens  as  many  fertile  as  the  lobes  of  the  corolla  and  opposite 

them.  Safotacea:. 

Group  6.  Ovary  free,  or  with  the  base  merely  coherent  with  the  tube  of  the 
calyx,  one-celled,  with  a  free  central  placenta.  Stamens  inserted  into  the 
regular  corolla  opposite  its  lobes  !  which  they  equal  in  number.  Seeds 
albuminous. 

Shrubs  or  trees  (all  tropical)  :  fruit  drupaceous.  Myrsinace;e. 

Herbs  :  fruit  capsular.  Primulace^e. 

Group  7.  Ovary  free,  one-celled,  with  a  single  ovule ;  or  two-celled  with 
several  ovules  attached  to  a  thick  central  placenta.  Stamens  as  many  as 
the  lobes  of  the  regular  corolla  or  the  nearly  distinct  petals.  Seeds  albu- 
minous. 

Ovary  two-celled  :  style  single  :  stamens  4,  or  rarely  less.  Plantaginace^:. 
Ovary  one-celled  :  styles  and  stamens  5.  Pi.umbaginace.iE. 

Group  8.     Ovary  free,  or  rarely  partly  coherent,  one-  or  two-  (or  spuriously 


430  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

four-)  celled,  with  numerous  ovules.     Corolla  bilabiate  or  irregular ;   the 
stamens  inserted  upon  its  tube,  and  mostly  fewer  than  its  lobes. 

Ovary  1 -celled  with  a  central  placenta.     Stamens  2.  Lentibulace.e. 

Ovary  1 -celled,  or  spuriously  2  -  5-celled  with  parietal  placenta;. 
Seeds  very  numerous  and  minute,  albuminous. 
Plants  destitute  of  green  herbage.  OrobanchacejE. 

Plants  with  green  herbage.  Gesneriace^e. 

Seeds  few  or  many,  large  :  albumen  none.  Bignoniace^e. 

Ovary  2-celled,  with  the  placenta  in  the  axis. 

Corolla  convolute  in  aestivation.     Seeds  few  ;  no  albumen.       Acanthaceve. 
Corolla  imbricated  in  aestivation.     Seeds  albuminous.       ScROPHULARiACEiE. 

Group  9.  Ovary  free,  two-  to  four-lobed,  or  at  least  separating  or  splitting 
into  as  many  one-seeded  nuts  or  achenia,  or  drupaceous.  Corolla  regular 
or  irregular ;  the  stamens  inserted  on  its  tube,  equal  in  number  or  fewer 
than  its  lobes.     Albumen  little  or  none. 

Stamens  4,  didynamous,  or  2.     Corolla  more  or  less  irregular. 

Ovary  not  4-lobed  :  style  terminal.  Verbenaceje. 

Ovary  of  4  lobes  around  the  base  of  the  style.  Labiates. 

Stamens  5.     Flower  regular.     Leaves  alternate.  Borraginace^e. 

Group  10.  Ovary  free,  compound,  or  rarely  the  carpels  two  or  more  and  dis- 
tinct :  the  ovules  usually  several  or  numerous.  Corolla  regular ;  the  sta- 
mens inserted  upon  its  tube,  as  many  as  the  lobes  and  alternate  with  them. 
Seeds  albuminous. 

Placentae  2,  parietal  (sometimes  expanded  or  united).     Embryo  minute. 

Hairy  herbs.     Albumen  cartilaginous.  HydrophyllacejE. 

Smooth  herbs.     Albumen  fleshy.  Gentianace^e. 

Placentae  in  the  axis  :  ovary  with  2,  3,  or  rarely  several  cells. 

Embryo  large,  coiled  or  folded.     Seeds  few.  •  Convolvulace^e. 

Embryo  straight,  with  broad  cotyledons.  PolemoniacejE. 

Embryo  curved,  rarely  straight,  slender.     Seeds  numerous.  Solanace^s. 

Group  11.  Ovaries  2  and  distinct  (or  sometimes  united),  but  the  stigmas  united 
into  one  and  often  the  styles  also.  Stamens  as  many  as  and  alternate  with 
the  lobes  of  the  regular  corolla,  which  is  convolute,  or  rarely  valvate  in 
aestivation.  Anthers  often  connected  with  the  stigma.  Fruit  usually  a  pair 
of  follicles.  Seeds  mostly  numerous,  often  comose.  Embryo  large  and 
straight,  in  sparing  albumen.     Juice  milky. 

Pollen  powdery.  Apocynaceje. 

Pollen  iu  waxy  or  granular  masses.  Asclepiadace^e. 

Group  12.  Ovary  free,  two-celled,  the  cells  mostly  two-ovuled,  and  the  fruit  one- 
seeded.  Corolla  regular  (sometimes  nearly  polypetalous  or  wanting) ;  the 
stamens  (two)  fewer  than  its  lobes.  —  Shrubs  or  trees. 

Seeds  erect.     Corolla  imbricated  or  contorted  in  aestivation.  Jasminace^e. 

Seeds  suspended.    Corolla  valvate  in  aestivation.  Oleace^s. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS.  431 

837.  Ord.  CaprifoliacefB  {Honeysuckle  Family).  Mostly  shrubs, 
often  twining,  with  opposite  leaves,  and  no  stipules  (but  Viburnum 
often  has  appendages  like  them).  Calyx-tube  adnate  to  the  2 -5- 
celled  ovary ;  the  limb  4  -  5-cleft.  Corolla  regular  or  irregular. 
Stamens  inserted  on  the  corolla,  as  many  as  the  petals  of  which  it  is 
composed,  and  alternate  with  them,  or  rarely  one  fewer.  Fruit 
mostly  a  berry  or  drupe.  Seeds  pendulous,  albuminous.  —  Ex.  The 
Honeysuckles  (Lonicera),  which  have  usually  a  peculiar  bilabiate 
corolla  (473),  the  Snowberry  (Symphoricarpus),  Diervilla,  which 
has  a  capsular  fruit,  &c,  compose  the  tribe  Loniceke.e,  character- 
ized by  their  tubular  flowers  and  filiform  style :  while  the  Elder 
(Sambucus)  and  Viburnum,  which  have  a  rotate  or  urn-shaped 
corolla,  form  the  tribe  Sambuce/e.     Chiefly  plants   of  temperate 


regions.  Several  species,  such  as  Honeysuckle,  &c,  are  widely 
cultivated  for  ornament.  They  are  generally  bitter,  and  rather 
active  or  nauseous  in  their  properties. 

838.  Ord.  RubiaceSB  {Madder  Family).  Shrubs  or  trees,  or  often 
herbs,  with  the  entire  leaves  either  in  whorls,  or  opposite  and  fur- 
nished with  stipules.     Calyx-tube  completely,  or  rarely  incompletely 

FIG.  859.  Branch  of  Lonicera  (Xylosteon)  oblongifolia:  the  two  ovaries  united!  860.  Lo- 
nicera (Caprifolium)  parviflora.  8G1.  A  flower  about  the  natural  size.  862.  Longitudinal  sec- 
tion of  the  ovary.  863.  Longitudinal  section  of  a  magnified  seed,  showing  the  albumen  and 
minute  embryo. 


432 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


adnate  to  the  2  -  5-celled  ovary ;  the  limb  four-  or  five-cleft  or 
toothed,  or  occasionally  obsolete.  Stamens  as  many  as  the  lobes  of 
the  regular  corolla,  and  alternate  with  them,  inserted  on  the  tube. 
Fruit  various.  Seeds  albuminous.  —  This  extensive  family  divides 
into  two  principal  suborders,  viz. :  — 

839.  Suboi'd.  Stellate JE  (Madder  Family  proper).  Herbs,  with  the 
leaves  in  whorls  ;  but  all  except  a  single  pair  are  generally  supposed 
to  take  the  place  of  stipules.  —  Ex.  Galium,  Rubia  (the  Madder), 
&c,  nearly  all  belonging  to  the  colder  parts  of  the  world.  The  roots 
of  Madder  yield  the  important  dye  of  that  name;  and  those  of 
several  species  of  Galium  are  imbued  with  a  similar  red  coloring- 
matter. 

840.  Subord.  Cinclioneae  (Peruvian-Bark  Family).  Shrubs,  trees, 
or  herbs  ;  the  leaves  opposite  and  furnished  with  stipules,  which  are 
very  various  in  form  and  appearance.  —  Ex.  Cephalanthus  (Button- 


brush),  Pinkneya,  and  an  immense  number  of  tropical  genera. 
Very  active,  and  generally  febrifugal  properties  prevail  in  this  large 
order.  It  furnishes  some  of  the  most  valuable  known  remedial 
agents,  among  them  Peruvian  Bark  or  Cinchona,  and  Ipecacuanha. 

FIG.  864.  Piece  of  Rubia  tinctoria  ( the  Madder)  in  flower.  865.  The  fruit.  866.  The  two 
constituent  portions  of  the  fruit  separating.  867.  Vertical  section  of  one  carpel,  showing  the 
curved  embryo.     808.  Section  of  a  flower  of  Galium. 

FIG.  869.  Cephalanthus  occidentalis,  the  Button-Bush.  870.  A  flower,  taken  from  the 
head.    871.  The  corolla  laid  open. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


433 


The  febrifugal  properties  of  the  former  depend  on  the  presence  of 
two  alkaloids, Cinchonia  and  Quinia,  both  combined  with  Kinic  acid. 
The  Quinquina  barks,  which  are  derived  from  some  species  of  Ex- 
ostemma  and  other  West  Indian,  Mexican,  and  Brazilian  genera, 
contain  neither  cinchonia  nor  quinia.  The  bark  of  Pinekneya  pu- 
bens,  of  the  Southern  United  States,  has  been  substituted  for  Cin- 
chona. —  The  true  Ipecacuanha  is  furnished  by  the  roots  of  Cepha- 
oalis  Ipecacuanha  of  Brazil  and  New  Granada.  Its  emetic  principle 
(called  Emetine)  also  exists  in  Psychotria  emetica  of  New  Granada, 
which  furnishes  the  striated,  black,  or  Peruvian  Ipecacuanha.  The 
order  likewise  furnishes  Coffee,  the  horny  seed  (albumen)  of  Coftrea 
Arabica.  According  to  Blume,  the  leaves  of  the  Coffee-plant  are 
used  as  a  substitute  for  tea  in  Java.  —  To  this  order  may  be  ap- 
pended, either  as  a  suborder,  or,  as  in  a  general  work  it  is  more  con- 
veniently regarded,  the 


841.  Ord.  LogailiaceiE,  which  may  be  briefly  said  to  be  Rubiaceas 
with  a  free  calyx,  and  manifestly  connected  with  the  Cinchonere 
through  the  Houstonia  section  of  Oldenlandia,  with  a  partly  free 

FIG.  S72.  Oldenlandia  (Houstonia)  eserulea.  873,  874.  The  two  sorts  of  flowers  that  differ- 
ent individuals  bear,  with  the  corolla  laid  open  ;  one  with  the  stamens  at  the  base,  the  other 
at  the  summit  of  the  tube  :  the  lower  figure  shows  also  a  section  of  the  ovary.  875.  Cross- 
section  of  an  anther,  magnified.  876  Anther  less  enlarged,  opening  longitudinally.  877. 
Capsule  with  the  calyx.  878,  879.  Views  of  the  capsule  in  dehiscence.  8S0.  Diagram  of  a 
cross-section  of  the  unexpanded  flower. 

37 


434 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


calyx.  On  the  other  hand,  they  run  close  to  Scrophulariacece  and 
Apocynaceaj.  —  Spigelia  Marilandica  (the  Carolina  Pink-root,  a 
well  known  vermifuge,  of  somewhat  acrid-narcotic  properties),  and 
Gelsemium  (the  so-called  Yellow  Jessamine  of  the  Southern  States) 
are  the  most  conspicuous  representatives  of  the  group  in  this  coun- 
try. The  active  properties  of  the  family  are  most  conspicuous  in 
species  of  Strychnos.  The  fatal  drug,  Nux-vomica,  from  which 
strychnine  is  extracted,  consists  of  the  seeds  of  an  East  Indian 
Strychnos.  Tieute,  another  frightful  poison,  is  prepared  from  a 
Java  species,  and  the  Ouari  poison  of  South  America,  from  a  third 
species.  Meanwhile  a  Brazilian  species,  S.  Pseudoquina,  has  a  harm- 
less fruit,  and  its  hark  (  Copalche  bark)  is  reputed  to  be  an  excellent 
febrifuge,  fully  equal  to  Cinchona. 

842.  Ord.  ValcriaiiacCSD  {Valerian  Family).  Herbs  with  opposite 
leaves,  and  no  stipules.  Flowers  often  in  cymes,  panicles,  or  heads. 
Limb  of  the  adnate  calyx  two-  to  four-toothed,  obsolete,  or  else 


forming  a  kind  of  pappus.  Corolla  tubular  or  funnel-form,  some- 
times with  a  spur  at  the  base,  four-  or  five-lobed.  Stamens  distinct, 
inserted  on  the  corolla,  usually  fewer  than  its  lobes.     Ovary  one- 

FIG.  881.  Branch  of  Fedia  Fagopyrum.  882.  A  magnified  flower.  883.  A  fruit.  884.  An 
enlarged  cross-section  of  the  same,  and  the  cotyledons  of  the  seed  in  the  single  fertile  cell :  the 
two  empty  cells  are  confluent  into  one.  885.  Flower  of  a  Valerian,  with  one  of  the  pappus- 
like bristles  of  the  calyx  unrolled.  886.  Section  through  the  ovary  and  embryo  ;  the  bristles 
of  the  calyx  broken  away. 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


435 


ovuled,  with  one  perfect  cell  and  two  abortive  ones.  Fruit  a  kind 
of  achenium.  Seed  suspended,  exalbuminous.  Embryo  straight, 
radicle  superior. — Ex.  Valeriana,  the  Valerian,  and  Fedia,  the  Lamb- 
Lettuce  :  the  latter  is  eaten  as  a  salad.  The  perennial  species, 
especially  the  roots,  exhale  a  heavy  and  peculiar  odor,  have  a  some- 
what bitter,  acrid  taste,  and  are  antispasmodic  and  vermifugal. 
Valerian  of  the  shops  is  chiefly  from  Valeriana  officinalis  of  the 
South  of  Europe.  It  produces  a  peculiar  intoxication  in  cats.  The 
large  roots  of  V.  edulis  are  eaten  by  the  aborigines  of  Oregon. 
The  famous  Spikenard  of  the  ancients,  esteemed  as  a  stimulant 
medicine  as  well  as  a  perfume,  is  the  root  of  a  Nardostachys  of  the 
Himalayas. 

843.  Ord.  Dipsaceft  (Teasel  Family).  Herbs,  with  opposite  or 
whorled  sessile  leaves,  destitute  of  stipules.  Flowers  in  dense 
heads,  which  are  surrounded  by  an  involucre.  Limb  of  the  adnate 
calyx  cup-shaped  and  entire  or  toothed,  or  forming  a  bristly  or 
plumose  pappus.  Corolla  tubular ;  the  limb  four-  or  five-lobed,  some- 
Avhat  irregular.  Stamens  four,  distinct,  or  rarely  united  in  pairs, 
often  unequal,  inserted  on  the  corolla.  Ovary  one-celled,  one-ovuled. 
Seed  suspended,  albuminous.  —  Ex.  Dipsacus,  the  Teasel,  and 
Scabiosa,  or  Scabious.  All  natives  of  the  Old  World.  Teasels  are 
the  dried  heads  of  Dipsacus  fullonum,  covered  with  stiff  and  spiny 
bracts,  with  recurved  points. 

844.  Ord.  Composite  (Composite  or  Sunflower  Family).  Herbs 
or  shrubs ;  with  the  flowers   in  heads    (compound  flowers   of  the 


older  botanists,  394,  Fig.  323  —  325),  crowded  on  a  receptacle,  and 
surrounded  by  a  set  of  bracts  (scales)  forming  an  involucre  ;  the  sep- 
arate flowers  often  furnished  with  bractlets  (chaff,  palece).  Limb  of 
the  adnate  calyx  obsolete,  or  a. pappus  (Fig.  569-573),  consisting 

FIG.  887.  A  head  of  flowers  of  Cichory  (Fig.  323)  vertically  divided. 


436  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

of  hairs,  bristles,  scales,  &c.  Corolla  regular  or  irregular.  Sta- 
mens five,  as  many  as  the  lobes  or  teeth  of  the  regular  corolla,  in- 
serted on  its  tube :  anthers  united  into  a  tube  (syngenesious,  Fig. 
463,  464).  Style  two-cleft.  Ovule  solitary,  erect,  anatropous. 
Fruit  an  achenium  (Fig.  568-573),  either  naked  or  crowned 
with  a  pappus.  Seed  destitute  of  albumenn.  Embryo  straight.  — 
This  vast  but  very  natural  family  is  divided  into  three  series  or 
suborders  ;  viz. :  — 

845.  Subord.  TubuliflorBC.  Corolla  tubular  and  regularly  four-  or 
five-lobed,  either  in  all  the  flowers  (when  the  head  is  discoid),  or  in 
the  central  ones  (those  of  the  disk)  only,  the  marginal  or  ray  flotvers 
presenting  a  ligidate  or  strap-shaped  corolla.  —  Ex.  Liatris,  Eupato- 
rium,  &c. ;  where  the  heads  are  homogamous,  that  is,  the  flowers  all 
tubular,  similar  and  perfect :  Helianthus  (Sunflower),  Helenium, 
Aster,  &c. ;  where  the  heads  are  heterogamous  ;  the  disk  flotvers 
being  tubular  and  perfect,  while  those  of  the  ray  are  ligidate,  and 
either  pistillate  only,  or  neutral,  that  is,  destitute  of  both  stamens 
and  pistils. 

846.  Sllbord.  Labiatiflorae.  Corolla  of  the  disk-flowers  bilabiate. — 
Ex.  Chaptalia,  of  the  Southern  United  States  ;  and  many  South 
American  genera,  &c. 

847.  Sllboi'd.  Liguliflora.  Corolla  of  the  flowers  (both  of  the  disk 
and  ray)  all  ligidate  and  perfect.  —  Ex.  The  Dandelion,  Lettuce, 
Cichory  (Fig.  887),  &c. 

848.  This  vast  family  comprises  about  a  tenth  part  of  all  Phoe- 
nogamous  plants.  A  bitter  and  astringent  principle  pervades  the 
whole  order ;  which  in  some  is  tonic  (as  in  the  Chamomile,  the 
Boneset  or  Thorough  wort,  &c.)  ;  in  others,  combined  with  mucilage, 
so  that  they  are  demulcent  as  well  as  tonic  (Elecampane  and  Colts- 
foot) ;  in  many,  aromatic  and  extremely  bitter  (such  as  Wormwood 
and  all  the  species  of  Artemisia)  ;  sometimes  accompanied  by  acrid 
qualities,  as  in  the  Tansy  and  the  Mayweed,  the  bruised  fresh  herb- 
age of  which  blisters  the  skin.  The  species  of  Liatris,  which  abound 
in  terebintliine  juice,  are  among  the  reputed  remedies  for  the  bites 
of  serpents ;  so  are  some  species  of  Mikania  in  Central  America. 
The  juice  of  Silphium  and  of  some  Sunflowers  is  resinous.  The 
leaves  of  Solidago  odora,  which  owe  their  pleasant  anisate  fragrance 
to  a  peculiar  volatile  oil,  are  infused  as  a  substitute  for  tea.  From 
the  seeds  of  Sunflower,  and  several  other  plants  of  the  order,  a  bland 
oil  is  expressed.     The  tubers  of  Helianthus  tuberosus  are  eaten 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


437 


under  the  name  of  Jerusalem  artichokes ;  Girasola,  the  Italian  name 
of  Sunflower,  having  become  Anglicized  into  Jerusalem.  True  arti- 
chokes are  the  fleshy  receptacle  and  imbricated  scales  of  Cynara 
Scolymus.  The  flowers  of  Carthamus  tinctorius,  often  called  Saf- 
fron, yield  a  yellow  dye,  much  inferior  in  quality  to  true  Saffron. 
—  The  Liguliflora?,  or  Cichoraceae,  all  have  a  milky  juice,  which  is 
narcotic,  and  has  been  employed  as  a  substitute  for  opium.  The 
bland  young  leaves  of  the  garden  Lettuce  are  a  common  salad.    The 


roasted  roots  of  the  Wild  Succory   (Cichorium  Intybus)   are  ex- 


no.  8SS.  Head  of  Liatris  squarrosa  (discoid  ;  the  flowers  all  tubular  and  perfect).  889. 
The  same,  with  the  scales  of  one  side  of  the  imbricated  involucre  removed  ;  and  also  all  the 
flowers  but  one,  showing  the  naked  flat  receptacle.  890.  Portion  of  one  of  the  plumose  bris- 
tles of  the  capillary  pappus.  891.  Head  of  Helenium  autumnale  (heterogamous) ;  the  rays 
neutral,  consisting  merely  of  a  ligulate  corolla.  892.  The  same,  with  the  flowers  all  removed 
from  the  roundish  receptacle,  except  a  single  disk-flower  and  one  or  two  rays :  the  reflexed 
scales  of  the  involucre  in  a  single  series.  893.  Magnified  disk-flower  of  the  same  :  the  corolla 
exhibiting  the  peculiar  venation  of  the  family  ;  namely,  the  veins  corresponding  to  the  sinuses, 
and  sending  a  branch  along  the  margins  of  the  lobes.  894.  The  same,  with  the  corolla  re- 
moved ;  the  achenium  crowned  with  the  limb  of  the  calyx  in  the  form  of  a  chaffy  pappus,  of 
about  five  scales.  895.  A  chaff  of  the  pappus  more  magnified.  896.  A  tubular  corolla  of  this 
family  laid  open,  showing  the  venation ;  and  also  the  five  syngenesious  anthers  united  in  a 
tube,  through  which  the  two-cleft  style  passes.  897.  Head  of  Dracopis  amplexicaulis,  with 
the  flowers  removed  from  the  elongated  spike-like  receptacle,  except  a  few  at  the  base :  a, 
achenium  of  one  of  the  disk-flowers  magnified,  partly  enclosed  by  its  bractlet  (chaff  or 
palea) ;  the  pappus  obsolete  898.  Part  of  the  involucre  and  alveolate  (honeycomb-like)  re- 
ceptacle of  Onopordon  or  Cotton-Thistle.  899.  A  perfect  and  ligulate  flower  of  the  Dandelion, 
with  its  hair-like  or  capillary  pappus. 

37* 


438 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


tensively  used  to  adulterate  coffee :  and  the  roots  of  some  species 
of  Tragopogon  (Salsify,  Oyster-plant)  and  Scorzonera  are  well- 
known  esculents. 

849.  Ordt  lobeliaceflB  {Lobelia  Family).  Herbs  or  somewhat 
shrubby  plants,  often  yielding  a  milky  juice,  with  alternate  leaves 
and  perfect  flowers.  Limb  of  the  adnate  calyx  five-cleft.  Corolla 
irregularly  five-lobed,  usually  appearing  bilabiate,  cleft  on  one  side 
nearly  or  quite  to  the  base.  Stamens  5,  epigynous,  coherent  into  a 
tube.  Stigma  fringed.  Capsule  one  -  several-celled,  many-seeded. 
Seeds  albuminous.  —  Ex.  Lobelia.  All  nareotico-acrid  poisons. 
The  well-known  Lobelia  inflata  (Indian  Tobacco)  is  one  of  the  most 
powerful  articles  of  the  materia  medica,  and  most  dangerous  in  the 
hands  of  the  reckless  quacks  who  use  it.  —  This  order  is  only  a 
form  of  the  next,  with  irregular  flowers. 

850.  Ord.  Campanulaceffi  {Campanula  Family).  Herbs,  like  the 
last,  but  the  juice  less  acrid,  and  the  corolla  regular,  campanulate, 


usually  five-lobed,  withering.     Stamens   five,  distinct.     Style   fur- 

FIG.  900.  Campanula  rotundifolia,  much  reduced  in  size.  901.  Lobelia  inflata,  reduced  in 
size.  902.  A  flower,  enlarged.  903.  The  united  filaments  and  anthers  enclosing  the  style  ;  tho 
corolla  and  limb  of  the  calyx  cut  away.  904.  The  stigma  surrounded  by  a  fringe.  905.  Trans- 
Terse  section  of  a  capsule.    90S.  Section  of  a  magnified  seed,  showing  the  embryo. 


EXOGENOUS    OR    DICOTYLEDONOUS    FLANTS. 


439 


nished  with  collecting  hairs.  —  Ex.  Campanula  (Bell-flower,  Hare- 
bell). Plants  of  little  known  importance  to  man,  except  for  or- 
nament. 

851.  Ortl.  EricaceSB  (Heath  Family).  Shrubs,  or  small  trees,  rarely 
herbs.  Flowers  regular  and  symmetrical,  or  nearly  so ;  the  petals 
sometimes  distinct.  Stamens  mostly  distinct,  free  from  the  corolla, 
as  many  or  twice  as  many  as  its  lobes,  and  inserted  with  it  (either 
hypogynous  or  epigynous)  :  anthers  often  appendaged,  commonly 
opening  by  terminal  pores.  Pollen  compound  (of  four  united 
grains)  except  in  the  last  suborder.  Styles  and  stigmas  united  into 
one.  Ovary  with  two  or  more  cells  and  usually  numerous  ovules, 
free,  or  in  Vaccineae  coherent  with  the  calyx-tube.  Seeds  usually 
indefinite,  albuminous.  —  Most  botanists  give  the  rank  of  orders  to 
the  following  suborders. 


852.  Suhord.  VaCCinieS  (  Whortleberry  Family).  Ovary  adnate  to 
the  tube  of  the  calyx,  becoming  a  berry  or  drupaceous.  Anthers 
two-celled ;  the  cells  nearly  distinct,  mostly  prolonged  above  into  a 
tube.  Shrubs,  with  scattered  or  alternate  leaves,  often  evergreen.  — 
Ex.  Vaccinium  (Bilberry,  Blueberry,  Cranberry)  and  Gaylussacia 
(Whortleberry  or  Huckleberry). 

853.  Subortl.  El'icinese  (True  Heath  Family).  Ovary  free  from 
the  calyx.  Fruit  capsular,  sometimes  baccate  or  drupaceous. 
Mostly  shrubs.  Leaves  various,  often  evergreen.  Petals  rarely 
distinct.  —  Ex.  Erica  (Heath),  Kalmia,  Rhododendron,  Gaultheria, 
Andromeda,  &c. 

FIG.  907.  Branch  of  Rhododendron  Lapponicum.  908.  Enlarged  flower,  with  its  pedicel  and 
bracts.  909.  A  flower  with  the  corolla  removed,  more  enlarged.  910.  The  capsule  of  It.  maxi- 
mum, opening  by  septicidal  dehiscence  ;  the  valves  breaking  away  from  the  persistent  axis, 
or  columella. 


440 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


854.  Sllbord.  Epacrideae  {Epacris  Family).  Shrubby  plants  of 
the  Southern  hemisphere,  with  the  aspect  and  character  of  Heaths, 
but  the  anthers  one-celled  are  not  appendaged. 

855.  Sllbord.  PyrolefE  {Pyrola  Family).  Ovary  free  from  the 
calyx.  Petals  distinct.  Anthers  two-celled.  Fruit  a  capsule. 
Seeds  with  a  very  loose  cellular  testa.  Mostly  herbs.  Leaves  flat 
and  broad,  evergreen.  —  Ex.  Pyrola,  Chimaphila. 


856.  Sllbord.  MonotropCfE  {Indian-Pipe  Family).  Ovary  free  from 
the  calyx.  Petals  distinct  or  united.  Anthers  two-celled,  or  con- 
fluently  one-celled.  Pollen  simple.  Fruit  a  capsule  Seeds  with 
a  loose  or  winged  testa.     Parasitic  herbs,  destitute  of  green  color, 


FIG.  911.  Gaultheria  procumbens  (Checkerberry,  &c.)  912.  The  enlarging  calyx  in  the  im- 
mature fruit.  913.  Vertical  section  of  the  pulpy  or  berry-like  calyx  and  the  included  capsule 
(the  seeds  removed  from  the  placenta  in  one  cell).  914.  Horizontal  section  of  the  same,  show- 
ing the  five-celled  capsule,  with  a  placenta  proceeding  from  the  inner  angle  of  each  cell.  915. 
Section  of  a  seed,  magnified.  916.  Flower  of  a  Vaccinium  (Blueberry).  917.  Vertical  sec- 
tion of  the  ovary  and  adherent  calyx.  918.  Anther  of  Vaccinium  Vitis-Idaea  ;  each  cell  pro- 
longed into  a  tube,  and  opening  by  a  terminal  pore.  919.  Anther  of  Vaccinium  Myrtillus ;  the 
connectivum  furnished  with  two  appendages.  920.  Stamen  of  an  Andromeda  (Cassiope),  show- 
ing the  appendages  of  the  connectivum.  921.  Stamen  of  Arctostaphylos  Uva-Ursi,  showing 
the  separate  anther-cells,  opening  by  a  terminal  pore,  the  appendages  of  the  connectivum,  and 
the  filament,  which  is  swollen  at  the  base. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS. 


441 


and  with  scales  instead  of  leaves.  —  Ex.  Monotropa,  the  Indian- 
Pipe  and  Pinesap. 

857.  In  this  diversified  and  widely  diffused  order,  the  bark  and 
foliage  are  generally  astringent,  often  stimulant  or  aromatic  from  a 
volatile  oil  or  a  resinous  matter,  and  not  seldom  narcotic.  Thus,  the 
leaves  of  Rhododendron,  Ivalmia,  and  all  the  related  plants,  are 
deleterious  (being  stimulant  narcotics),  or  suspicious.  The  honey 
made  from  their  flowers  is  sometimes  poisonous.  The  Uva-Ursi 
and  the  Chimaphila  (Pipsissewa)  are  the  chief  medicinal  plants  of 


the  order.  The  berries  are  generally  edible,  and  some  are  largely 
used  for  the  dessert ;  as  Cranberries,  Blueberries,  and  Huckleber- 
ries. The  fleshy  calyx  of  Gaultheria  (Checkerberry,  or  Winter- 
green)  has  a  very  pleasant  and  well-known  aroma.  Many  Ericaceae 
are  cultivated  for  ornament,  especially  Rhododendrons  and  Azaleas, 
Heaths  and  Epacrises. 


FIG.  922.  Pyrola  chlorantha,  reduced  in  size.  923.  Enlarged  flower.  924.  Magnified  sta- 
men. 925.  Pistil.  926.  Cross-section  of  the  capsule.  927.  A  highly  magnified  seed.  928.  The 
nucleus  removed  from  the  loose  cellular  testa,  and  divided,  showing  the  very  minute  embryo. 

FIG.  929.  Monotropa  uniflora.  930.  A  petal.  931.  Capsule,  with  the  stamens.  932.  Trans- 
verse section  of  the  same ;  the  thick  and  lobed  placenta  covered  with  very  minute  seeds. 


442 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


858.  Ord.  AqilifoliaceSB  (Holly  Family).  Trees  or  shrubs,  com- 
monly with  coriaceous  leaves,  and  small  axillary  polygamous  flowers. 
Calyx  of  four  to  six  sepals.  Corolla  four-  to  six-parted  or  cleft : 
the  stamens  as  many  as  its  segments  and  alternate  with  them,  in- 
serted on  the  base  of  the  corolla.  Anthers  opening  longitudinally. 
Ovary  two-  to  six-celled ;  the  cells  with  a  single  suspended  ovule. 
Fruit  drupaceous,  with  two  to  six  nutlets.  Embryo  minute,  in  hard 
albumen.  —  Ex.  Ilex,  the  Holly,  &c.  The  bark  and  leaves  contain 
a  tonic,  bitter,  extractive  matter.  The  leaves  of  a  species  of  Ilex 
are  used  for  tea  in  Paraguay :  and  the  famous  black  drink  of  the 
Creek  Indians  is  prepared  from  the  leaves  of  Ilex  vomitoria  (Cas- 
sena)  ;  which  are  still  used  as  a  substitute  for  tea  in  some  parts  of 
the  Southern  States. 

859.  Ol'd.  EbenacCfC  (Ebony  Family).  Trees  or  shrubs,  destitute 
of  milky  juice,  with  alternate,  mostly  entire  leaves,  and  polygamous 
flowers.  Calyx  three-  to  six-cleft,  free  from  the  ovary.  Corolla 
three-  to  six-cleft,  often  pubescent.  Stamens  twice  to  four  times  as 
many  as  the  lobes  of  the  corolla,  inserted  on  them.  Ovary  three-  to 
several-celled ;  the  style  with  as  many  divisions.  Fruit  a  kind  of 
berry,  with  large  and  bony  seeds.     Embryo  shorter  than  the  hard 


albumen.  —  Ex.  Diospyros,  the  Persimmon.  The  fruit,  which  is 
extremely  austere  and  astringent  when  green,  becomes  sweet  and 
eatable  when  fully  ripe.  The  bark  is  powerfully  astringent.  Eb- 
ony is  the  wood  of  Diospyros  Ebenus  and  other  African  and  Asiatic 
species. 

860.  Ol'd.  Stymcaceae  (Storax  Family).     Shrubs  or  trees,  with  per- 

FIG.  933.  Perfect  flower  of  Diospyros  Virginiana,  the  Persimmon.  931.  The  corolla,  laid 
open,  and  stamens.  935.  The  fruit.  93G.  Section  through  the  fruit  and  bony  seeds.  937. 
A'ertical  section  of  a  seed.    938.  The  detached  embryo. 


EXOGENOUS    OR    DICOTYLEDONOUS    TLANTS.  443 

feet  flowers.  Calyx-tube  generally  coherent  either  with  the  base  of 
the  ovary,  or  with  its  whole  surface.  Petals  often  distinct  or  nearly 
so.  Styles  and  stigmas  perfectly  united  into  one.  Stamens  definite, 
or  in  the  suborder  Symplocine^e  mostly  indefinite  ;  filaments  more 
or  less  united.  Cells  of  the  ovary  opposite  the  calyx-lobes.  Other- 
wise much  as  in  the  last  family.  —  Ex.  Styrax,  Halesia,  Symplocos. 
Some  yield  a  fragrant,  balsamic  resinous  substance  ;  such  as  Storax 
and  Benzoin,  containing  Benzoic  acid.  The  sweet  leaves  of  our 
Symplocos  tinctoria  afford  a  yellow  dye. 

861.  Ord.  Sapotaceffi  (Sapodilla  Family).  Trees  or  shrubs,  usually 
with  a  milky  juice  ;  the  leaves  alternate,  entire,  coriaceous,  the  up- 
per surface  commonly  shining.  Flowers  perfect,  regular,  axillary, 
usually  in  clusters.  Corolla  four-  to  eight-  (or  many-)  cleft.  Sta- 
mens distinct,  inserted  on  the  tube  of  the  corolla,  commonly  twice 
as  many  as  its  lobes,  half  of  them  fertile  and  opposite  the  lobes,  the 
others  petaloid  scales  or  filaments  and  alternate  with  them  :  anthers 
extrorse.  Ovary  4-12-celled,  with  a  single  ovule  in  each  cell. 
Styles  united  into  one.  Fruit  a  berry.  Seeds  with  a  bony  testa, 
with  or  without  albumen.  —  Ex.  Bumelia,  of  the  Southern  United 
States.  The  fruit  of  many  species  is  sweet  and  eatable ;  such  as 
the  Sapodilla  Plum,  the  Marmalade,  the  Star- Apple,  and  other  "West 
Indian  species.  The  large  seeds,  particularly  of  some  kinds  of 
Bassia,  yield  a  bland  fixed  oil,  which  is  sometimes  thick  and  like 
butter,  as  in  the  Chee  of  India  (B.  butyracea),  and  the  African 
Butter-tree. 

862.  Ol'd.  MjTSinacea1.  Trees  or  shrubs,  mostly  with  alternate 
coriaceous  leaves,  which  are  often  dotted  with  glands,  and  with  all 
the  characters  of  Primulacea?,  except  the  drupaceous  fruit  and  arbo- 
rescent habit.  —  Nearly  all  tropical  (Ardisia,  Myrsine). 

863.  Ord.  PrimulaceSB  {Primrose  Family).  Herbs,  with  opposite, 
whorled,  or  alternate  leaves,  often  with  naked  scapes  and  the  leaves 
crowded  at  the  base.  Flowers  regular.  Stamens  inserted  on  the 
tube  of  the  corolla,  as  many  as  its  lobes  and  opposite  them  !  Ovary 
free,  with  one  partial  exception,  one-celled  with  a  free  central  pla- 
centa!  Ovules  mostly  indefinite  and  amphitropous.  Style  and 
stigma  single.  Fruit  capsular :  the  fleshy  central  placenta  attached 
to  the  base  of  the  cell.  Seeds  albuminous.  Embryo  transverse.  — 
Ex.  Primula  (Primrose),  Cyclamen,  Anagallis.  In  Samolus,  the 
calyx  coheres  with  the  base  of  the  ovary,  and  there  is  a  row  of 
sterile   filaments   occupying  the  normal  position  of  the  first  set  of 


444 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


stamens,  namely,  alternate  with  the  lohes  of  the  corolla.     Several 
are  ornamental  in  cultivation,  such  as  Primroses  and  Auriculas. 


864.  Ortl.  PlantaginaceEB  {Plantain  Family).  Chiefly  low  herbs, 
with  small  spiked  flowers  on  scapes,  and  ribbed  radical  leaves.  — 
Calyx  four-cleft,  persistent.  Corolla  tubular  or  urn-shaped,  scarious 
and  persistent ;  the  limb  four-cleft.  Stamens  four,  rarely  two,  in- 
serted on  the  tube  of  the  corolla  alternate  with  its  segments  ;  the  per- 
sistent filaments  long  and  flaccid.  Ovary  two-celled :  style  single. 
Capsule  membranaceous,  circumcissile ;  the  cells  one-  to  several- 
seeded.  Embryo  large,  straight,  hi  fleshy  albumen.  —  Ex.  Plantago, 
the  Plantain,  or  Ribgrass,  is  the  principal  genus  of  the  order.  Of  no 
important  economical  qualities. 

865.  Ol'd.  Plumbagiliacese    {Leadioort  Family).     Perennial  herbs, 

FIG.  939.  Primula  Mistassinica.  940.  The  corolla  removed;  its  tube  laid  open.  941.  The 
calyx  divided  vertically,  showing  the  pistil.  942.  Vertical  section  of  the  ovary  and  of  the  free 
central  placenta,  covered  with  ovules,  which  nearly  fills  the  cell.  943.  Capsule  of  Primula 
veris,  dehiscent  at  the  summit  by  numerous  teeth.  944.  A  magnified  seed.  945.  Section  of 
the  same,  exhibiting  the  transverse  embryo. 

FIG.  946.  Branch  of  Anagallis  arvensis  (Pimpernel),  with  a  capsule  showing  the  line  of  cir- 
cumcissile dehiscence.    947.  The  capsule  (pyxis),  with  the  lid  falling  away. 


EXOGENOUS    OK   DICOTYLEDONOUS    PLANTS. 


445 


or  somewhat  shrubby  plants ;  with  the  flowers  often  on  simple  or 
branching  scapes,  and  the  leaves  crowded  at  the  base,  entire,  mostly 
sheathing  or  clasping.  —  Calyx  tubular,  plaited,  five-toothed,  persist- 
ent. Corolla  salver-shaped,  with  a  five-parted  limb,  the  five  stamens 
inserted  on  the  receptacle  opposite  its  lobes  (Plumbago)  ;  or  else  of 
five  almost  distinct  unguiculate  (scarious  or  coriaceous)  petals,  with 
the  stamens  inserted  on  their  claws !  (Statice,  &c.)     In  the  former 


949  9.8  957 

case  the  five  styles  are  united  nearly  to  the  top ;  but  in  the  latter 
they  are  separate  !  Ovary  one-celled,  with  a  single  ovule  pendulous 
from  a  strap-shaped  funiculus  which  rises  from  the  base  of  the  cell. 
Fruit  a  utricle,  or  opening  by  five  valves.  Embryo  large,  in  thin 
albumen.  —  Ex.  Statice  (Marsh-Rosemary  or  Sea-Lavender)  and 
Armeria  (Thrift)  ;  sea-side  or  saline  plants.  They  have  astringent 
roots  ;  none  more  so  than  those  of  our  own  Marsh-Rosemary  or  Sea- 
Lavender,  one  of  the  purest  astringents  of  the  materia  medica. 

866.  Ord.  LentiblllaceSB  {Bladdemcort  Family).  Small  herbs,  grow- 
ing in  water,  or  wet  places,  with  the  flowers  on  scapes  ;  the  leaves 
either  submersed  and  dissected  into  filiform  segments  resembling 
rootlets,  and  commonly  furnished  with  air-bladders  to  render  them 

FIG.  948.  A  flower  of  Plantago  major,  enlarged.  949.  Pistil.  950  Capsule  (pyxis,)  with 
the  marcescent  corolla.    951.  Cross-section  of  a  pod  and  seeds.    952.  Vertical  section  of  a  seed. 

PIG.  953.  Corolla,  and  954,  calyx  of  Thrift  (Armeria  vulgaris).  955.  Pistil  with  distinct 
styles.  956  Cross-section  of  the  pod  and  seed.  957.  Vertical  section  of  the  ovary,  magnified, 
to  show  the  ovule. 

38 


446 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


buoyant,  sometimes  evanescent  or  wanting,  or  when  produced  in 
the  air  entire  and  somewhat  fleshy,  clustered  at  the  base  of  the 
scape.  Flowers  showy,  very  irregular.  Calyx  of  two  sepals,  or 
unequally  five-parted.  Corolla  bilabiate,  personate  ;  the  very  short 
tube  spurred.  Stamens  two,  inserted  on  the  upper  lip  of  the  co- 
rolla: anthers  confluently  one-celled.  Ovary  free,  one-celled  with  a 
free  central  placenta  !  bearing  numerous  ovules.  Seeds  destitute  of 
albumen.  Embryo  straight.  —  Ex.  Utricularia  (Bladderwort),  Pin- 
guicula.     Unimportant  plants. 

867.  Ord.  Orobaiicliaceffi  {Broom-Rape  Family).  Herbs,  destitute 
of  green  foliage,  and  with  scales  in  place  of  leaves,  parasitic  on  the 
roots  of  other  plants.  Corolla  withering  or  persistent,  with  a  bila- 
biate or  more  or  less  irregular  limb.     Stamens  four,  didynamous, 


inserted  on  the  corolla.     Ovary  free,  one-celled,  with  two  parietal 
placenta; !  which  are  often  two-lobed,  or  divided.     Capsule  enclosed 

FIG.  958.  Branch  of  Epiphegus  Tirginiana  (Beech-drops),  nearly  of  the  natural  size :  the 
lower  flowers,  with  short  imperfect  corollas,  alone  producing  ripe  seeds.  959.  A  flower  en- 
larged. 960.  Longitudinal  section  of  the  same.  961.  Longitudinal  section  of  the  ovary,  more 
magnified,  showing  one  of  the  parietal  placentae  covered  with  minute  ovules.  962.  Cross-sec- 
tion of  the  same,  showing  the  two  parietal  placentae.  963.  A  highly  magnified  seed.  964. 
Section  of  the  same,  exhibiting  the  minute  embryo  next  the  hilum. 

FIG.  965.  Aphyllou  uniflorum.  966.  A  flower  about  the  size  of  nature.  967.  The  same 
laid  open,  showing  the  didynamous  stamens  and  the  pistil.  908.  A  magnified  anther.  969.  A 
magnified  seed.    970.  Section  of  the  same. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS.  447 

in  the  persistent  corolla.  Seeds  very  numerous,  minute.  Embryo 
minute  at  the  extremity  of  the  albumen.  —  Ex.  Orobanche,  Epi- 
phegus  (Beech-drops),  &c.  Astringent,  bitter,  and  escharotic.  The 
pulverized  root  of  Epiphegus  (thence  called  Cancer-root)  is  applied 
to  open  cancers. 

868.  Ord.  GeslieriaCCDE,  consisting  chiefly  of  tropical  herbs  or  tender 
shrubby  plants,  with  green  foliage  and  showy  flowers,  the  calyx 
often  partly  adherent  to  the  ovary,  agrees  with  Orobanchacere  in  the 
parietal  placentation,  structure  of  the  seeds,  &c.  Many  are  culti- 
vated in  conservatories  for  ornament,  such  as  species  of  Gloxinia 
and  Achimenes. 

869.  Ol'd.  Biglioniaceffi  {Bignonia  Family).  Mostly  trees,  or 
climbing  or  twining  shrubby  plants,  with  large  and  showy  flowers, 
and  opposite,  simple,  or  mostly  pinnately-compound  leaves.  Corolla 
with  a  more  or  less  irregular  five-lobed  or  bilabiate  limb.  Stamens 
five,  of  which  one,  and  often  three,  are  reduced  to  sterile  filaments 
or  rudiments  (Fig.  409),  or  four  and  didynamous.  Ovary  one- 
celled  with  two  parietal  placenta?,  or  two-celled  by  a  false  partition 
stretched  between  the  placentae,  or  rarely  by  their  meeting  in  the 
axis.  Pod  two-valved,  many-seeded.  Seeds  winged  (Fig.  601), 
destitute  of  albumen.  Cotyledons  foliaceous,  flat,  heart-shaped,  also 
notched  at  the  apex.  —  Ex.  Bignonia,  Tecoma  (Trumpet-creeper), 
Catalpa,  and  other  tropical  genera.  Of  little  importance,  except  as 
ornamental  plants. 

870.  Sllbord.  Sesamca;  (Sesamum  Family)  has  few  and  wingless 
seeds ;  the  fruit  generally  indurated  or  drupaceous,  often  two-  to 
four-horned,  sometimes  perforated  in  the  centre  from  the  dissepi- 
ments not  reaching  the  axis  before  they  diverge  and  become  pla- 
centiferous,  and  spuriously  four-  to  eight-celled  by  the  cohesion  of 
parts  of  the  placenta?  with  the  walls  of  the  pericai'p.  —  Ex.  Sesa- 
mum, Marty nia  (Unicorn-plant),  and  a  few  tropical  plants.  They 
are  mucilaginous  ;  and  the  seeds  of  Sesamum  yield  a  good  fixed  oil. 

871.  Sllbord.  CrescentieSB,  consists  of  the  Calabash-tree  (Crescentia 
Cujete)  and  a  few  allies,  among  them  Parmentiera  edulis,  the  Can- 
dle-tree of  Panama,  which  also  have  wingless  seeds.  The  subacid 
pulp  of  the  gourd-like  fruit  is  edible ;  the  hard  shell  is  used  for  bot- 
tles, or  calabashes. 

872.  Ord.  Acanthaceffi  {Acanthus  Family).  Herbs  or  shrubby 
plants,  Avith  bracteate  showy  flowers,  and  opposite  simple  leaves, 
without  stipules.     Corolla  bilabiate,  or  sometimes  almost  regularly 


448 


ILLUSTRATIONS    OF   THE   NATURAL    ORDERS. 


five-lobed,  convolute  in  aestivation !  Stamens  four  and  didynamous, 
oi'  only  two,  the  anterior  pair  being  abortive  or  obsolete.  Ovary 
two-celled,  with  the  placentae  in  the  axis,  often  few-ovuled.  Seeds 
(sometimes  only  one  or  two  in  each  cell)  usually  supported  by 
hooked  processes  of  the  placenta,  destitute  of  albumen.  The  classi- 
cal Acanthus  is  the  type  of  this  large  and  chiefly  tropical  order :  its 
gracefully  lobed  and  sinuated  leaves  furnished  the  ornament  of  the 
Corinthian  capital.  They  are  emollient  plants,  or  some  of  them 
bitter  or  slightly  acrid  :  of  little  economical  use.  Several  are  culti- 
vated for  ornament. 

873.  Ol'd.   Scroplmlariaceffi   (Figivort  Family).      Herbs,  or  some- 
times shrubby  plants,  with  opposite,  verticillate,  or  alternate  leaves. 


977       971  974  978  973   976 

Corolla  bilabiate,  or  more  or  less  irregular ;  the  lobes  imbricated  in 
aestivation.  Stamens  four  and  didynamous  (Fig.  407),  the  fifth  or 
upper  stamen  sometimes  appearing  in  the  form  of  a  sterile  filament 

FIG.  971.  Branch  of  Gerardia  purpurea.  972.  Corolla,  of  the  natural  size,  laid  open.  973. 
Calyx  and  style  of  the  same.  974.  Magnified  transverse  section  of  the  capsule,  with  one  of  the 
ralves  removed. 

FIG.  975.  Gratiola  aurea,  natural  size.  976.  Corolla  laid  open,  showing  the  two  perfect 
stamens  and  two  rudimentary  filaments  as  well  as  the  pistil.  977.  The  perfect  stamens  and 
sterile  filament  of  Chelone.    978.  Flower  of  a  Linaria  (Toadflax). 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


449 


(Fig.  408),  or  very  rarely  antheriferous,  or  often  only  two,  one 
pair  being  either  suppressed  or  reduced  to  sterile  filaments.  Ovary 
free,  two-celled,  with  the  placenta?  united  in  the  axis.  Capsule  two- 
valved.  Seeds  indefinite,  or  sometimes  few,  albuminous.  Embryo 
small.  —  Ex.  Scrophularia,  Verbascum  (Mullein,  which  is  remarkable 
for  the  almost  regular  corolla,  and  the  five  often  nearly  perfect  sta- 
mens), Linaria,  Antirrhinum  (Snapdragon),  <&■.  —  The  plants  of  this 
large  and  important  order  are  generally  to  be  suspected  of  delete- 
rious (bitter,  acrid,  or  drastic)  properties.  The  most  important  me- 
dicinal plant  is  the  Foxglove  (Digitalis  purpurea),  so  remarkable  for 
its  power  of  lowering  the  pulse.  Numerous  species  are  cultivated 
for  ornament. 

874.  Orel.  Yei'benaceOE  (  Vervain  Family).  Herbs,  shrubs,  or  often 
trees  in  the  tropics,  mostly  with  opposite  leaves.  Corolla  bilabiate, 
or  the  four-  or  five-lobed  limb  more  or  less  irregular.  Stamens 
mostly  four  and  didynamous,  occasionally  only  two.     Ovary  free, 


entire,  two-  to  four-celled.  Fruit  drupaceous,  baccate,  or  dry,  and 
splitting  into  two  to  four  indehiscent  one-seeded  portions.  Seeds  with 
little  or  no  albumen.  Embryo  straight,  inferior.  —  Ex.  Verbena 
(Vervain)  is  the  principal  representative  in  cooler  regions.  There 
are  many  others  in  the  tropics ;  one  of  which  is  the  gigantic  Indian 
Teak  (Tectona  grandis),  remarkable  for  its  very  heavy  and  durable 

FIG.  979  ana  980.  Flower  of  a  Verbena  enlarged.  9S1.  The  corolla  laid  open.  982.  Pistil. 
983.  The  fruit.  984.  Cross-section  of  the  young  fruit  and  the  contained  seeds.  985.  Fruit 
separating  into  its  four  cocci.  986.  Cross-section  of  one  of  the  cocci,  and  a  vertical  section  of 
the  lower  part,  showing  the  surface  of  the  contained  seed.  987.  Vertical  section  through 
the  pericarp,  seed,  and  embryo. 

38* 


450 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


wood.     The  leaves  of  Lippia  eitridora  of  the  gardens  yield  an  agree- 
able perfume.     Others  are  bitter  and  aromatic. 

875.  Sllbord.  ?  PlirymaceCB  (founded  on  Phryma,  of  a  single  species) 
is  separated  on  account  of  its  simple  pistil,  uniovulate  ovary,  spirally 
convolute  cotyledons,  and  superior  radicle. 

876.  Ord.  LabiatflC  {Labiate  or  Mint  Family).  Herbs,  or  some- 
what shrubby  plants,  with  quadrangular  stems,  and  opposite  or 
sometimes  whorled  leaves,  replete  with  receptacles  of  volatile  oil. 
Flowers  in  axillary  cymules,  rarely  solitary.  Corolla  bilabiate  (Fig. 
458).  Stamens  four,  didynamous,  or  only  two,  one  of  the  pairs 
being  abortive  or  wanting.  Ovary  free,  deeply  four-lobed  ;  the  cen- 
tral style  proceeding  from  between  the  lobes.  Fruit  consisting  of 
four  (or  fewer)  little  nuts  or  achenia,  included  in  the  persistent 
calyx.     Seeds  with  little  or  no  albumen.  —  Ex.  The   Sage,  Rose- 


mary, Lavender,  Thyme,  Mint,  &c.  are  familiar  representatives  of 
this  universally  recognized  order.  Their  well-known  cordial,  aro- 
matic, and  stomachic  qualities  depend  upon  a  volatile  oil,  contained 
in  glandular  receptacles  which  abound  in  the  leaves  and  other  her- 
baceous parts,  with  which  a  bitter  principle  is  variously  mixed. 

877.  Ord.  BorragiliacefC   {Borage  Family).     Herbs,  or  sometimes 
shrubby  plants,  with  round  stems,  and  alternate  rough  leaves  ;  the 

FIG.  9S8.  Flower  of  Nepeta  (Gleehoma)  hederacea,  or  Ground  Ivy.  989.  Approximate 
anthers  of  one  pair  of  stamens,  magnified.  990.  Flower  of  a  Lamium.  991.  Corolla  of  L. 
amplexicaule  (Dead  Nettle),  laid  open,  showing  the  didynamous  stamens,  &c.  992.  Calyx  and 
corolla  of  Scutellaria  galericulata  (Skull-cap).  993.  Section  of  the  enlarged  calyx  of  the  same, 
bringing  to  view  the  deeply  four-lobed  ovary.  994.  Cross-section  of  a  magnified  achenium. 
995.  Vertical  section  of  the  same,  showing  the  embryo.  996.  Flower  of  Teucrium  Cauadense. 
997.  Magnified  anther  of  the  same.  998.  Stamen  of  the  Thyme.  999.  Flower  of  Monarda. 
1000.  Magnified  anther  of  the  same.  1001.  Flower  of  a  Salvia  ;  the  calyx  as  well  as  the  corolla 
bilabiate.  1002.  Magnified  stamen  of  the  same,  with  widely  separated  anther-cells,  one  of 
which  (a)  is  polliuiferous,  the  other  (6)  imperfect. 


EXOGENOUS    OK    DICOTYLEDONOUS    PLANTS. 


451 


flowers  often  in  one-sided  scorpioid  clusters  (407).  Calyx  of  five 
leafy  and  persistent  sepals,  more  or  less  united  at  the  base,  regular. 
Corolla  regular ;  the  limb  five-lobed,  often  with  a  row  of  scales  in 
the  throat.  Stamens  as  many  as  its  lobes  and  alternate  with  them. 
Ovary  deeply  four-lobed,  the  style  proceeding  from  the  base  of  the 
lobes,  which  in  fruit  become  little  nuts  or  hard  achenia.  Seeds  with 
little  or  no  albumen.  —  Ex.  Borage,  Lithospermum,  Myosotis,  Cyno- 
glossum  (Hound's-Tongue),  Heliotropium,  &c.  In  Echium,  the  limb 
of  the  corolla  is  somewhat  irregular,  and  the  stamens  unequal.  In- 
nocent mucilaginous  plants  with  a  slight  astringency :  hence  demul- 
cent and  pectoral ;  as  the  roots  of  the  Comfrey.     The  roots  of  An- 


chusa  tinctoria  (Alkanet)  and  Lithospermum  canescens,  &c.  (used 
by  the  aborigines  under  the  name  of  Puccoon)  yield  a  red  dye. 

878.  Sllbord.  ?  CordiaceSB  consists  of  tropical  woody  plants,  with 
the  ovary  entire  (not  four-lobed),  but  in  fruit  drupaceous  or  dry  and 
indehiscent,  four-seeded.  The  cotyledons  of  Cordia  are  plaited  lon- 
gitudinally (and  are  often  edible),  and  the  style  is  twice  forked. 

879.  Ol'd.  HydropliyllacetC  ( Water-leaf  Family).  Herbs,  usually 
with  alternate  and  lobed  or  pinnatifid  leaves ;  the  flowers  mostly 
in  cymose  clusters  or  unilateral  racemes.     Calyx  five-cleft,  with  the 

FIG.  1003.  Myosotis,  or  Forget-me-not.  1004.  The  rotate  corolla  laid  open,  showing  the 
scales  of  the  throat,  and  the  short  stamens.  1005.  The  pistil,  with  its  four-lobed  ovary.  1006. 
The  calyx  in  fruit ;  two  of  the  little  nuts  having  fallen  away  from  the  receptacle.  1007.  Sec- 
tion of  a  nut,  or  rather  achenium,  showing  the  embryo.  1008  Raceme  of  Symphytum  offici- 
nale (Comfrey).  1009.  A  corolla  laid  open ;  exhibiting  the  lanceolate  and  pointed  scales  of  the 
throat,  alternate  with  the  stamens. 


452 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


sinuses  often  appendaged,  persistent.  Corolla  regular,  imbricated  or 
convolute  in  aestivation,  usually  furnished  with  scales  or  honey-bear- 
ing grooves  inside  ;  the  five  stamens  inserted  into  its  base,  alternate 
with  the  lobes.  Ovary  free,  with  two  parietal  placentas,  which  in 
Hydrophyllum  dilate  in  the  cell  and  appear  like  a  kind  of  inner  peri- 


carp in  the  capsular  fruit.  Styles  partly  united.  Seeds  few,  or 
sometimes  numerous,  amphitropous,  crustaceous.  Embryo  small, 
in  hard  albumen.  —  Ex.  Hydrophyllum,  Nemophila,  and  Phacelia ; 
neai'ly  all  North  American  plants,  some  of  them  handsome  and  now 
well  known  in  cultivation.  To  this  order,  as  a  tribe,  is  now  joined 
the  Hydrole^e  (formerly  the  order  Hydroleacece),  having  often 
entire  leaves,  two  distinct  styles,  a  commonly  two-celled  ovary  by 
the  union  of  the  two  placentas  in  the  axis,  and  numerous  seeds 
with  a  fleshy  albumen.  These  are  chiefly  tropical  or  subtropical 
herbs,  or  low  shrubs. 


FIG.  1010.  Hydrophyllum  Virginicum.  1011.  A  flower,  nearly  of  the  natural  size.  1012. 
Corolla  laid  open.  1013.  Capsule,  with  the  persistent  calyx  and  style.  1014.  Magnified  seed. 
1015.  Section  of  the  same.     1016.  Highly  magnified  embryo. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


453 


880.  Ol'd.  Polenioniaceae  {Polemonium  Family).     Herbs,  with  alter- 
nate or  opposite  leaves,  and  panicled,  corymbose,  or  clustered  flow- 


ers.    Calyx  five-cleft.     Corolla  regular,  with  a  five-lobed  limb,  con- 
volute in  aestivation.     Stamens  five,  inserted  on  the  corolla  alternate 


with  its  lobes,  often  unequal.     Ovary  free,  three-celled,  with  a  thick 

FIG.  1017.  Flowers  of  Polemonium.  1018.  Flowers  of  Phlox.  1019.  Corolla  of  the  same, 
laid  open,  showing  the  stamens  unequally  inserted  on  its  tube.  1020.  Pistil  of  the  same. 
1021.  Cross-section  of  the  capsule  of  Polemonium.  1022.  Cross-section  of  a  magnified  seed. 
1023.  Perpendicular  section  of  the  same.  1024.  Magnified  embryo.  1025.  Cross-section  of  the 
dehiscent  capsule  of  Collomia.     1026,  1027.  Capsule  of  Leptodactylon. 

FIG.  1028.  Pyxidanthera  barbulata,  of  the  Pine-barrens  of  New  Jersey,  natural  size.  1029. 
Pistil,  in  fruit,  and  calyx,  enlarged.  1030.  Corolla  and  stamens.  1031.  Same,  laid  open. 
1032.   A  separate  stamen,  maguified.    1033.  Section  of  the  dehiscent  capsule.     1034.  A  seed. 


454 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


axis,  bearing  few  or  numerous  ovules :  styles  united  into  one  :  stig- 
mas three.  Capsule  three-valved,  loculicidal ;  the  valves  also  usu- 
ally breaking  away  from  a  thick  central  column  which  bears  the 
seeds.  Embryo  straight,  in  fleshy  or  horny  albumen.  —  Ex.  Pole- 
monium  (Greek  Valerian),  Phlox,  Gilia.  Chiefly  North  Amer- 
ican ;  many  are  very  common  ornamental  plants  in  cultivation.  To 
this  order  Diapensia  and  Pyxidanthera  (formerly  the  order  Dia- 
pensiacece)  are  now  appended,  with  some  doubt.  They  are  two 
low,  tufted  or  prostrate,  suffruticose  plants,  with  crowded  and  ever- 
green, heath-like  leaves,  and  solitary  flowers  :  their  principal  peculi- 
aiuty  is  found  in  the  transversely  dehiscent  anthers. 

881.  Ol'd.  CuilYOlvulaceSB  {Convolvulus  Family).  Twining  or  trail- 
ing herbs  or  shrubs,  with  more  or  less  milky  juice  ;  the  leaves  alter- 
nate, and  the  flowers  regular.  Calyx  of  five  imbricated  sepals,  per- 
sistent. Corolla  supervolute  in  ajstivation  ;  the  limb  often  entire 
(Fig.  452).  Stamens  five,  inserted  on  the  tube  of  the  corolla  near 
the  base.  Ovary  free,  two-  to  four-celled,  with  one  or  two  erect 
ovules  in  each  cell.  Capsule  two-  to  four-  (or  by  obliteration  one-) 
celled ;  the  valves  often  falling  away  from  the  persistent  dissepi- 
ments (septifragal,  Fig.  587).  Seeds  large,  with  a  little  mucilagi- 
nous albumen  :  embryo  curved,  and  the  foliaceous  cotyledons  usually 


crumpled  (Fig.  122,  123). — Ex.  Morning-Glory,  Bindweed.     They 
contain   a  peculiar   strongly   purgative   resinous    matter,  which   is 

FIG.  1035.  Ipomoea  purpurea.  1036.  The  pistil.  1037-  Section  of  the  capsule,  and  of  the 
two  seeds  in  each  cell.  1038.  Capsule  (reduced  in  size),  when  the  valves  have  fallen  away  from 
the  dissepiments ;  and  one  of  the  seeds.  1039.  Magnified  cross-section  of  a  seed.  1040.  Em- 
bryo, with  the  leaf  like  two-lobed  cotyledons  spread  out.  1041.  Same,  with  the  two  cotyledons 
separated  and  laid  open. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


455 


chiefly  found  in  their  thickened  or  tuberous  roots.  Convolvulus 
Jalapa,  and  other  Mexican  species,  furnish  the  Jalap  of  the  shops. 
The  more  drastic  Scammony  is  derived  from  the  roots  of  C.  Scam- 
monia  of  the  Levant.  There  is  much  less  of  this  in  those  of  Con- 
volvulus panduratus  (Man-of-the-Earth,  "Wild  Potato-vine)  :  while 
those  of  C.  macrorhizus  of  the  Southern  States,  which  sometimes 
weigh  forty  or  fifty  pounds,  arc  farinaceous,  with  so  slight  an  ad- 
mixture of  this  matter  as  to  be  quite  inert ;  as  is  also  the  case  with 
the  Batatas,  or  Sweet  Potato,  an  important  article  of  food.  —  To  this 
family  are  appended,  as  tribes  or  suborders, 

882.  Sllbord.  Dicliondrea1.  Ovaries  two  to  four,  either  entirely 
distinct  or  with  their  basilar  styles  more  or  less  united  in  pairs. 
Creeping  plants,  with  axillary,  scape-like,  one-flowered  peduncles.  — 
Ex.  Dichondra. 

883.  Sllbord.  CusCUtlliese.  Ovary  two-celled ;  the  capsule  opening 
by  circumcissile  dehiscence,  or  bursting  irregularly.  Embryo  fili- 
form, and  spirally  coiled  in  fleshy  albumen,  destitute  of  cotyledons  ! 


Parasitic,  leafless,  twining  herbs,  destitute  of  green  color.     Stamens 
usually  furnished  with  fringed  scales  within.  — Ex.  Cuscuta  (Dodder). 


FIG.  1042.  A  piece  of  Cuscuta  Gronovii,  the  common  Dodder  of  the  Northern  United  States, 
of  the  natural  size.  1013.  A  flower,  enlarged.  1044.  The  same,  laid  open.  1045.  Section  of 
the  ovary.  1046.  Section  of  the  capsule  and  seeds.  1047.  The  spiral  embryo  detached.  1048. 
The  same  in  germination. 


456 


ILLUSTRATIONS    OF    THE   NATURAL    ORDERS. 


884.  Ol'd.  SolanaceOB  {Nightshade  Family)  differs  from  Scrophu- 
lariaceae  chiefly  in  the  regular  (rarely  somewhat  irregular)  flowers, 
with  as  many  fertile  stamens  as  there  are  lobes  to  the  corolla  (four 
or  five),  and  some  form  of  the  plaited  or  valvate  aestivation  of  the 
corolla.  Fruit  either  capsular  or  baccate.  Embryo  slender,  mostly 
curved,  in  fleshy  albumen  (Fig.  614,  615).  —  The  fruit  of  Datura 
is  spuriously  four-celled.  —  Stimulant  narcotic  properties  pervade  the 
order,  the  herbage  and  fruits  of  which  are  mostly  deleterious,  often 
violently  poisonous,  and  furnish  some  of  the  most  active  medi- 
cines ;  such  as  the  Tobacco,  the  Henbane  (Hyoscyamus  niger),  the 


Belladonna  (Atropa  Belladonna),  the  Thorn-apple  or  Jamestown 
Weed  (Datura  Stramonium),  and  the  Bittersweet  (Solanum  Dulca- 
mara). Yet  the  berries  of  some  Solanums  are  eatable  (as  Toma- 
toes, the  Egg-Plant,  &c),  and  the  starchy  tubers  of  the  Potato 
are  a  great  staple  of  food.  But  the  fruit  and  seeds  of  Capsicum 
(  Cayenne  pepper)  are  most  pungent  and  stimulant. 

885.  Ol'd.  GeiltianaceiE  {Gentian  Family).  Herbs,  with  a  watery 
juice  ;  the  leaves  opposite  and  entire.  Flowers  regular,  often  showy. 
Calyx  of  usually  four  or  five  persistent,  more  or  less  united  sepals. 
Corolla  mostly  convolute  in  aestivation ;  the  stamens  inserted  on  its 
tube.  Ovary  one-celled,  with  two  parietal  and  many-ovuled  pla- 
ne 1049.  Flower  of  Tobacco  (Nicotiana  Tabacum).  1050.  The  capsule,  dehiscent  at  the 
apex,  with  the  persistent  calyx.  1051.  Cross-section  of  the  same.  1052.  Magnified  section  of 
the  seed  of  Solanum.  1053.  Flower  of  Hyoscyamus  niger.  1054.  Fruit  (pyxis)  of  the  same. 
1055.  Flowers  and  berries  of  Solanum  Dulcamara. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS. 


457 


centa?,  sometimes  the  ovules  dispersed  over  the  whole  cavity  of  the 
ovary,  or  nearly  so.  Capsule  many-seeded.  Seeds  often  very  small, 
with  fleshy  albumen  and  a  minute  embryo.  —  Ex.  Gentiana,  Frasera 
(the  American  Columbo).  A  pure  bitter  and  tonic  principle  ( Gen- 
tianine)  pervades  the  whole  order.  Gentiana  lutea  of  Middle 
Europe  furnishes  the  officinal  Gentian,  for  which  almost  any  of  our 
species  may  be  substituted.  The  above  applies  to  the  proper  Gen- 
tian Family.     Obolaria  differs  in  the  imbricative  aestivation  of  the 


corolla :  as  to  the  ovules  lining  the  whole  cavity  of  the  ovary,  this 
is  also  the  case  in  Bartonia  (Centaurella,  Michx.),  and  in  some  Gen- 
tians.—  The  Buckbean  is  the  type  of  the  tribe  Menyanthideje, 
which  has  alternate,  sometimes  trifoliolate  or  toothed  leaves,  and  a 
valvate-induplicate  aestivation  of  the  corolla. 

886.  Ol'd.  ApocynacefC  {Dogbane  Family).  Trees,  shrubs,  or  herbs, 
with  milky  juice,  and  opposite  entire  leaves,  without  stipules. 
Flowers  regular.  Corolla  five-lobed,  mostly  convolute  or  twisted 
in  aestivation.  Filaments  distinct ;  the  anthers  sometimes  slightly 
connected :  pollen  powdery.  Ovaries  two,  distinct,  or  rarely  syn- 
carpous,  but  their  styles  or  stigmas  combined  into  one.  Fruit  com- 
monly a  pair  of  two  follicles.  Seeds  often  with  a  coma.  Embryo 
large  and  straight,  in  albumen. — Ex.  Apocynum  (Dogbane),  Vinca 

FIG.  1056.  Flower  of  Gentiana  angustifolia  1057.  Corolla,  and  1058,  the  calyx,  laid  open. 
1059.  The  pistil.  1060.  Cross-section  of  the  pistil,  showing  the  parietal  attachment  of  the 
ovules.  1061.  Fiipe  capsule  of  G.  saponaria,  raised  on  a  stipe :  the  persistent  withering 
corolla,  &c  torn  away.  1062.  A  magnified  seed,  with  its  large  and  loose  testa.  1063.  Leaf  of 
Limnanthemuin  lacunosum,  bearing  the  flowers  on  its  petiole  ! 

39 


458 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


(Periwinkle),  Nerium  (Oleander),  and  a  great  number  of  tropical 
shrubs  and  trees.  In  nearly  all,  the  juice  is  drastic  or  poisonous ; 
it  often  yields  Caoutchouc  ;  which  in  Sumatra  is  obtained  from  Ur- 
ceola  elastica,  and  in  Madagascar  from  Vahea.  Strangely  enough 
some  species  yield  a  sweet  and  harmless  milk,  such  as  Tabemae- 
montana  utilis,  one  of  the  South  American  Cow-trees.  Also  the 
fruit  of  several  species  is  edible  and  even  delicious  ;  that  of  others 
is  a  deadly  poison.      One  kernel  of  Tanghinia  venenifera  of  Mad- 


agascar will  kill  twenty  people.     The  inner  bark  of  Dogbane  makes 
a  strong  cordage,  whence  its  name  of  Indian  Hemp. 

887.  Ord.  AsckpiadaceSB  {Milkweed  Family).  Herbs  or  shrubs, 
with  milky  juice,  and  mostly  opposite  entire  leaves;  mainly  differ- 
ing from  the  preceding  order  (as  they  do  from  all  other  Exogenous 
plants)  by  the  peculiar  connection  of  the  stamens  with  the  stigma, 
and  the  cohesion  of  the  pollen  into  wax-like  or  granular  masses, 
which  are  attached  in  pairs  to  five  glands  of  the  stigma,  and  re- 
moved from  the  anther-cells  usually  by  the  agency  of  insects  (Fig. 
541-545).  Fruit  consisting  of  two  follicles.  Seeds  usually  with 
a  silky  coma  and  a  large  embryo.  —  Ex.  Asclepias  (Milkweed,  or 
Silk  weed).  The  juice  of  the  A.  tuberosa  (Pleurisy-root,  Butterfly- 
weed)  is  not  milky.  In  all,  it  is  bitter  and  acrid,  and  contains 
Caoutchouc.  The  roots,  &c.  are  diaphoretic,  emetic,  or  cathartic. 
The  inner  bai-k  yields  abundance  of  very  long  and  fine,  extremely 

FIG.  1064.  Apocynum  androsoernifolium.  IOCS.  Flower,  of  the  natural  size.  1066.  Sta- 
mens with  the  anthers  conniveut  around  the  pistils.  1067.  The  pistils  with  their  large  com- 
mon stigma.    1068.  Seed  with  its  coma,  or  tuft  of  silky  hairs. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


459 


strong  fibres.     The  singular  structure  of  the  blossom  may  be  learned 
from  Fig.  541  -  545,  and  the  subjoined  illustrations. 


888.  Ord.  JasmiliacefC  {Jessamine  Family)  consists  of  a  few  chiefly 
Asiatic  shrubs,  with  compound  leaves  and  fragrant  flowers  ;  differ- 
ing from  Oleacea?  by  the  imbricated  or  twisted  aestivation  of  the 
hypocrateriform  corolla,"  the  erect  seeds,  &c.  —  Ex.  Jasminum,  the 
Jessamine.  Cultivated  for  ornament,  and  for  their  very  fragrant 
blossoms.  —  Menodora,  or  Bolivaria,  has  mostly  simple  leaves  and 
four  ovules  in  each  cell,  but  evidently  pertains  to  this  order. 

889.  Ord.  OleacCflB  {Olive  Family).  Trees  or  shrubs,  with  oppo- 
site leaves,  either  simple  or  pinnate.     Calyx  persistent.     Corolla 

FIG.  1069.  Flower-bud  of  the  common  Milkweed  (Asclepias  Cornuti).  1070.  Expanded 
flower  ;  the  calyx  and  corolla  reflexed ;  showing  the  stamiueal  crown.  1072.  One  of  the  hood- 
ed appendages  of  the  latter  removed  and  seen  sidewise,  with  its  included  process  or  horn. 
1073.  A  vertical  section  of  a  flower  (the  hooded  appendages  removed)  through  the  tube  of  sta- 
mens, the  thick  stigma,  ovaries,  &c.  1074.  Flower  with  the  calyx,  and  the  fertilized  enlarging 
ovaries,  crowned  with  the  large  stigma  common  to  the  two,  from  the  angles  of  the  peltate  sum- 
mit of  which  the  pairs  of  pollen-masses,  detached  from  the  anther  cells,  hang  by  their  stalks  or 
caudicle  from  a  gland.  1075.  Fruit  (follicle)  of  the  Common  Milkweed.  1076.  Cross-section 
of  the  last,  in  an  early  state.  1077.  Detached  placenta  in  fruit,  covered  with  seeds.  1078. 
Seed  (cut  across),  with  its  coma.  1079.  Section  of  the  seed,  parallel  with  the  cotyledons. 
1080.  Vertical  section  of  the  seed  perpendicular  to  the  face  of  the  cotyledons. 


460  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

four-cleft,  or  of  four  separate  petals,  valvate  in  aestivation,  sometimes 
none.  Stamens  mostly  two,  adnate  to  the  base  of  the  corolla. 
Ovary  free,  two-celled,  with  two  pendulous  ovules  in  each  cell. 
Fruit  by  suppression  usually  one-celled  and  one-  or  two-seeded. 
Seed  albuminous.  Embryo  straight.  —  Ex.  Olea  (the  Olive),  and 
Chionanthus  (Fringe-tree),  where  the  fruit  is  a  drupe.  Syringa,  the 
Lilac,  which  has  a  capsular  fruit.  Fraxinus,  the  Ash ;  where  the 
fruit  is  a  samara,  the  flowers  are  polygamous,  and  mostly  destitute 
of  petals.  Olive  oil  is  expressed  from  the  esculent  drupes  of  Olea 
Europaea.  The  bark,  like  that  of  the  Ash,  is  bitter,  astringent,  and 
febrifugal.  Manna  exudes  from  the  trunk  of  Fraxinus  Ornus  of 
Southern  Europe,  &c.  —  Forestiera  appears  to  represent  another 
entirely  apetalous  form  of  this  family. 


Division  III.  —  Apetalous  Exogenous  Plants. 

Corolla  none  ;  the  floral  envelopes  consisting  of  a  single  series 
(calyx),  or  sometimes  entirely  Avanting.  —  Many  of  them  are  apeta- 
lous allies  of  polypetalous  families  ;  as  Phytolaccacea?,  &c.  related  to 
Caryophyllaceae ;  Empetraceas  to  Ericaceae,  &c. 

Conspectus  of  the  Orders. 

Group  1 .  Flowers  perfect,  with  a  conspicuous  or  colored  mostly  adnate  calyx. 
Ovary  several-celled  and  many-ovuled.  Capsule  or  berry  many-seeded.  — 
Herbs  or  climbing  shrubs.  Aristolochiace^;. 

Group  2.  Flowers  perfect,  or  rarely  polygamous.  Calyx  corolline,  strongly 
gamosepalous,  much  produced  beyond  the  ovary,  the  expanded  border  entire 
or  moderately  lobed ;  the  base  persistent,  and  forming  an  indurated  nut- 
like  closed  covering  to  the  one-seeded  achenium  or  utricle.  Embryo  large, 
curved  or  conduplicate,  involving  some  albumen.  —  Leaves  opposite  :  nodes 
tumid.   Flowers  often  large  and  showy.  Nyctaginace^e. 

Group  3.  Flowers  perfect,  or  rarely  polygamous,  with  a  regular  and  often 
pctaloid  calyx.  Ovary  free.  Ovules  solitary  in  each  ovary  or  cell.  Em- 
bryo curved  or  coiled  around  (or  sometimes  in)  mealy  albumen,  rarely  in  the 
axis  or  exalbuminous. 

Ovary  several-celled,  or  ovaries  several  in  a  whorl.  Phytolaccacea:. 

Ovary  solitary  and  one-celled,  with  a  single  ovule. 

Stipules  none.     Ovule  campylotropous  or  amphitropous. 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS.  461 

Calyx  corolline,  double.     Stamens  perigynous.  Baseixaceje. 

Calyx  not  corolline  :  no  scarious  bracts.  Chenopodiaceje. 

Calyx  and  bracts  scarious,  sometimes  colored.  Amarantace;e. 

Stipules  sheathing.     Calyx  corolline.     Ovule  orthotropous.    Polygonace^e. 

Group  4.  Flowers  perfect,  polygamous  or  dioecious,  not  disposed  in  aments, 
with  a  regular  and  often  petaloid  calyx.  Style  or  stigma  one.  Ovaiy 
one-celled,  with  one  or  few  ovules  :  but  the  fruit  one-celled  and  one-seeded. 
Embryo  not  coiled  around  albumen.  —  Trees  or  shrubs,  rarely  herbs. 

Calyx  free  from  the  ovary,  and  not  enveloping  the  fruit. 

Flowers  polygamo-dicecious.     Anthers  opening  by  valves.  Lauraceje. 

Flowers  perfect.     Anthers  opening  longitudinally.  Tuymelace.e. 

Calyx  free,  but  baccate  in  fruit  and  enclosing  the  achenium.  Eleagnaceje. 
Calyx  adnate  to  the  ovary.     Ovule  destitute  of  coats. 

Ovules  several,  pendulous  from  a  stipe-like  placenta.  Santalace.e. 

Ovule  solitary,  suspended-     Parasitic  shrubs.  Loranthace^e. 

Group  5.  Flowers  perfect,  in  spikes  which  often  appear  like  aments,  achlamyde- 
ous.  Ovaries  solitary  or  several,  with  one  or  few  erect  or  ascending 
orthotropous  ovules.  Embryo  minute,  enclosed  in  a  persistent  embryo-sac 
at  the  apex  of  the  albumen.  —  Herbs  or  shrubby  plants,  with  tumid  nodes. 

Ovaiy  one,  one-ovuled.     Stipule  opposite  the  leaf  or  none.  Piperace^e. 

Ovaries  more  than  one.     Stipules,  when  present,  in  pairs.  SaururacejE. 

Group  6.  Flowers  perfect  or  diclinous,  frequently  destitute  of  both  calyx  and 
corolla.  —  Submersed  or  floating  aquatic  herbs. 

Flowers  monoecious.     Fruit  one-celled,  one-seeded.  Ceratopiiyllace^e. 

Flowers  mostly  perfect.     Fruit  four-celled,  four-seeded.  Callitrichace^e. 

Flowers  mostly  perfect.    Pod  several-celled,  several-seeded.      Podostemace^:. 

Group  7.  Flowers  monoecious  or  dioecious,  not  amentaceous.  Fruit  capsular 
or  drupaceous,  with  two  or  more  cells,  and  one  (or  rarely  two)  seeds  in 
each  cell.  Embryo  straight  in  the  axis  of  the  albumen.  —  Herbs,  shrubs, 
or  trees. 

Fruit  mostly  dry.    Juice  milky.     Pollen  simple.  Euphorbiace^:. 

Fruit  drupaceous.     Pollen  compound  ;  the  grains  in  fours.  Empetrace-e. 

Group  8.  Flowers  monoecious,  dioecious,  or  polygamous,  with  a  regular  calyx 
which  is  free  from  the  one-celled  (or  rarely  two-celled)  ovary  and  one- 
seeded  fruit  (achenium,  drupe,  or  samara),  but  sometimes  enclosing  it. 
Embryo  curved,  or  straight,  with  the  radicle  superior,  in  albumen  when 
there  is  any.  —  Inflorescence  various,  often  in  spikes,  heads,  or  a  sort  of 
aments.  Urticace^e. 

Group  9.    Flowers  monoecious  or  dioecious,  the  sterile,  and  frequently  the  fertile 
also,  in  aments,  or  in  heads  or  spikes.     Calyx  of  the  fertile  flowers,  if  any, 
adherent.     Ovary  often  two-  to  several-celled,  but  the  fruit  always  one- 
celled.  —  Trees  or  shrubs. 
39* 


462 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


Stipules  sheathing.     Nutlets  club-shaped,  in  globular  heads. 
Stipules  not  sheathing  or  none. 
Sterile  flowers  only  amentaceous. 
Fruit  a  kind  of  drupaceous  nut.    Leaves  pinnate. 
Fruit  a  dry  nut,  involucrate.     Leaves  simple. 
Both  kinds  of  flowers  amentaceous. 
Fruit  a  samara  or  a  small  dry  drupe. 
Ovary  one-celled  :  ovule  solitary,  erect. 
Ovary  two-celled,  two-ovuled  :  ovule  pendulous. 
Fruit  a  many-seeded  follicle  :  seeds  with  a  coma. 


PlATANACEjE. 


JuGLANDACEjE. 
CurULIFEKiG. 


Myricaceje. 
Betulace^e. 

Salicace^e. 


890.  Ord.  AristoIochiaceaB  (Birthiuort  Family).  Herbaceous  or 
climbing  shrubby  plants,  with  alternate  leaves.  Flowers  brown 
or  greenish,  usually  solitary.  Calyx-tube  more  or  less  united  with 
the  ovary  ;  the  limb  valvate.  Stamens  six  to  twelve,  epigynous,  or 
adherent  to  the  base  of  the  short  and  thick  style :  anthers  adnate, 


1081  1085  1082 

extrorse.  Ovary  3  -  6-celled.  Capsule  or  berry  three-  to  six-celled, 
many-seeded.  Embryo  minute,  in  fleshy  albumen.  —  Ex.  Asarum 
(Wild  Ginger,  Canada  Snakeroot),  Aristolochia  (Virginia  Snake- 
root).  Pungent,  aromatic,  or  stimulant  tonics  ;  generally  termed 
Snakeroots,  being  reputed  antidotes  for  the  bites  of  venomous  snakes. 

FIG.  1081.  Asarum  Canadense.  1082.  Calyx  displayed,  and  a  vertical  section  through  the 
rest  of  the  flower.  1083.  Cross-section  of  the  ovary  ;  the  upper  portion  (from  which  the  limb 
of  the  calyx  is  cut  away)  showing  the  stamens,  the  united  styles,  &c.  10SI.  A  separate  sta- 
men, enlarged.     1085.  Vertical  section  of  a  seed. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


463 


891.  Ord.  RafflesiaceEC  :  parasitic  flowers,  or  flower-clusters  (152),  of 
which  the  most  striking  is  the  gigantic  Rafflesia  Arnoldi  of  Sumatra 
(Fig.  150),  perhaps  as  much  related  to  the  last  order  as  to  any. 

892.  Ord.  NjXtaginacefC  (Four-o'clock  Family).  Herbs  or  shrubs, 
with  opposite  leaves  ;  distinguished  by  their  tubular  and  funnel-form 
calyx,  the  upper  part  of  which  resembles  a  corolla,  and  at  length 
separates  from  the  base,  which  latter  hardens  and  encloses  the  one- 
celled  achenium-like  fruit,  appearing  like  a  part  of  it.  Stamens  hy- 
pogynous,  1  -  20.  Embryo  coiled  around  mealy  albumen  (Fig.  G16, 
G17)  ;  cotyledons  large.  Flowers  involucrate.  Mirabilis  (Four- 
o'clock)  has  a  one-flowered  involucre  exactly  like  a  calyx,  while  the 
real  calyx  resembles  the  corolla  of  a  Morning-Glory.  Abronia  has 
only  one  cotyledon  to  its  embryo  !  —  Plants  of  warm  latitudes  ;  many 
occur  on  our  Southwestern  frontiers. 


1090  1092  1091  1086 


893.  Ol'll.  PhytolaCCaceOE  (Poke-weed  Family).     Chiefly  represented 

FIG  1086,  10S7.  Phytolacca  decandra  (Pokeweed).  1088.  A  flower.  1089.  Unripe  fruit. 
1090.  Cross-section  of  the  same,  a  little  enlarged.  1091.  Maguified  seed.  1092.  Section  of  the 
same  across  the  embryo.  1093.  Vertical  section,  showing  the  embryo  coiled  around  the  albu- 
men into  a  ring.    1094.  Magnified  detached  embryo. 


464 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


by  the  common  Poke  (Phytolacca  decandra),  which  has  a  compound 
ovary  of  ten  confluent  (one-seeded)  carpels,  the  short  styles  or  stig- 
mas distinct ;  the  fruit  a  berry.  The  root  is  acrid  and  emetic :  yet 
the  young  shoots  in  the  spring  are  used  as  a  substitute  for  Aspara- 
gus.    The  berries  yield  a  copious  deep-crimson  juice. 

894.  Ol'd.  BascllaceCB ;  a  small  subtropical  group  of  climbing  suc- 
culent plants,  allied  to  the  last  and  the  next  two  orders,  from  which 
it  differs  by  the  decidedly  perigynous  stamens  and  double  petaloid 
calyx.  The  ovary  is  single  and  one-ovuled.  —  Ex.  Basella,  Bous- 
singaultia  of  South  America ;  the  latter  cultivated  for  ornament  (from 
potato-like  tubers)  under  the  name  of  Madeira  Vine.  Some  are  pot- 
herbs. 

895.  Ord.  Clienopodiacea;  (Goosefoot  Family).  Chiefly  weedy 
herbs,  with  alternate  or  opposite  and  more  or  less  succulent  leaves, 


1103 


and  small  herbaceous  flowers.  Calyx  sometimes  tubular  at  the 
base,  persistent ;  the  stamens  as  many  as  its  lobes,  or  fewer,  and  in- 
serted at  their  base.  Ovary  free,  one-celled,  with  a  single  ovule 
arising  from  its  base.  Fruit  a  utricle  (Fig.  574)  or  achenium. 
Embryo  curved  or  coiled  around  the  outside  of  mealy  albumen,  or 
spiral  without  any  albumen  (in  Salsola,  &e.) .  —  Ex.  Chenopodium, 
Atriplex,  Beta  (the  Beet),  &c.     Sea-side  plants,  or  common  weeds  : 


FIG.  1095.  Part  of  the  spike  of  Salicornia  herbaeea :  the  flowers  placed  three  together  in 
excavations  of  the  stem,  protected  by  a  fleshy  scale.  1096.  Separate  flower.  1097.  A  flower 
of  Blitum,  with  its  fleshy  calyx  and  single  stamen.  1098.  Same,  more  enlarged,  with  the  thick- 
ened juicy  calyx  (1099)  removed.  1100.  The  ripe  fruit.  1101.  Same,  divided  vertically,  show- 
ing the  embryo  coiled  around  the  central  albumen.  1102.  Flower  of  Chenopodium  album 
(common  Goosefoot).  1103.  Section  of  the  same,  more  enlarged.  1104.  Section  of  the  utricle 
and  seed,  showing  the  embryo.  1105.  Calyx  of  Salsola  kali  (Saltwort),  in  fruit,  with  its  wing- 
like border.  1106.  Section  of  the  same,  bringing  the  ovary  into  view.  1107.  The  spirally 
coiled  embryo  of  Chenopodina  maritinia. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


465 


some  are  pot-herbs,  such  as  Spinach  :  a  few  are  cultivated  for  their 
esculent  roots  ;  as  the  Beet,  which  yields  sugar.  Soda  is  extract- 
ed from  the  maritime  species,  especially  from  those  of  Salsola  and 
Salicornia  (Samphire,  Glass- wort).  Chenopodium  anthelminticum 
yields  the  well-known  Worm-seed  oil. 

896.  Ord.  AlMMHtaceffi  {Amaranth  Family).  Flowers  in  heads, 
spikes,  or  dense  clusters,  imbricated  with  dry  and  scarious  bracts 
which  are  often  colored.  Calyx  of  three  to  five  sepals,  which  are 
dry  and  scarious  like  the  bracts.  Stamens  five  or  fewer,  hypogy- 
nous,  distinct  or  monadelphous :  anthers  frequently  one-celled.  Utri- 
cle often  opening  as  a  pyxis  (Fig.  575).  Embryo  annular,  always 
vertical.  Otherwise  nearly  as  in  Chenopodiacere. —  Amarantus, 
&c.  A  few  Amaranths  (Coxcomb,  &c.)  and  Globe  Amaranths 
(Gomphrena)  are  cultivated  for  ornament.  But  most  of  the  family 
are  coarse  and  homely  weeds  (Pigweeds,  &c). 


897.  Ord.  PolygonacCfE    {Buckwheat  Family).     Herbs  with  alter- 
nate leaves  ;  remarkable  for  their  stipules  (ochreze,  Fig.  305),  which 


FIG.  1108.  Polygonum  Pennsylvanicum.  1109.  Flower,  laid  open.  1110.  Section  of  the 
ovary,  showing  the  erect  ovule.  1111.  Section  of  the  seed,  showing  the  embryo,  at  one  side  of 
albumen. 


466 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


usually  form  sheaths  around  the  stems  above  the  leaves,  and  for 
their  orthotropous  ovules  (Fig.  518, 526).  Stamens  definite,  inserted 
on  the  petaloid  calyx.  Fruit  achenium-like.  Embryo  curved,  or 
nearly  straight,  applied  to  the  outside  (rarely  in  the  centre)  of 
starchy  albumen  (Fig.  606).  —  Ex.  Polygonum,  Rumex  (Dock, 
Sorrel),  Rheum  (Rhubarb).  The  stems  and  leaves  of  Rhubarb 
and  Sorrel  are  pleasantly  acid :  while  several  Polygonums  (Knot- 
weed,  Smart-weed,  Water  Pepper,  &c.)  are  acrid  or  rubefacient. 
The  farinaceous  seeds  of  P.  Fagopyrum  (the  Buckwheat)  are  used 
for  food.  The  roots  of  most  species  of  Rhubarb  are  purgative  :  but 
it  is  not  yet  known  what  particular  species  of  Tartary  yields  the 
genuine  officinal  article.  The  Eriogone^e  (a  large  tribe  of  the 
southern  and  Avestern  parts  of  North  America,  chiefly  west  of  the 
Rocky  Mountains)  are  remarkable  for  their  exstipulate  leaves  and 
involucrate  flowers. 

898.  Ord.  LauraceOB  {Laurel  Family).  Trees  or  shrubs,  with 
pellucid-punctate  alternate  leaves,  their  margins  entire.  Flowers 
sometimes  polygamo-dioecious.  Calyx  of  four  to  six  somewhat 
united  petaloid  sepals,  which  are  imbricated  in  two  series,  free 
from  the  ovary.  Stamens  definite,  but  usually  more  numerous  than 
the  sepals,  inserted  on  the  base  of  the  calyx  :  anthers  two-  to  four- 
celled,  opening  by  recurved  valves  !  Fruit  a  berry  or  drupe,  the 
pedicel  often  thickened.     Seed  with  a  large  almond-like  embryo, 


destitute  of  albumen.  —  Ex.  Laurus,  Sassafras,  Benzoin.     All  aro- 
matic plants,  almost  every  part  abounding  in  warm  and  stimulant 


FIG.  1112.  A  staminate,  and  1113,  a  pistillate  flower  of  Sassafras.  1114.  A  stamen  with  its 
glands  at  the  base  :  the  anthers  opening  by  two  sets  of  valves.  1115.  Pistil ;  the  ovary  divid- 
ed.    1116    Branch  in  fruit.    1117.  Section  of  the  drupe  and  seed. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


467 


volatile  oil,  to  which  their  qualities  are  due.  Camphor  is  obtained 
from  Camphora  officinarum  of  Japan,  China,  &c.  Cinnamon  is  the 
bark  of  Cinnamornum  Zeylanicum ;  Cassia  bark,  of  Cinnamomum 
aromaticum  of  China.  The  aromatic  bark  and  wood  and  the  very 
mucilaginous  leaves  of  our  own  Sassafras  are  well  known.  Our 
Benzoin  odoriferum  is  the  Spice-wood,  or  Feverbush.  Laurus 
nobilis  is  the  true  Laurel,  or  Sweet  Bay.  Persea  gratissima,  of  the 
West  Indies,  bears  the  edible  Avocado  pear. 

899.  Ord.  Tliymclacese  (Mezereum  Family).  Shrubby  plants,  with 
perfect  flowers,  and  a  very  tough  bark ;  the  tube  of  the  petaloid 
calyx  being  free  from  the  (one-ovuled)  ovary  ;  its  lobes  imbricated 
in  aestivation ;  the  pendulous  seed  destitute  of  albumen.  Stamens 
often  twice  as  many  as  the  lobes  of  the  calyx,  inserted  upon  its  tube 


or  throat.  —  Ex.  Daphne  and  Dirca  (Leather-wood,  Moose-wood, 
Wickopy,  which  is  the  only  North  American  genus).  The  tough 
bark  is  acrid,  or  even  blistering,  and  is  also  useful  for  cordage.  The 
reticulated  fibres  of  the  liber  in  the  Lagetta  or  Lace-bark  of  Jamaica 
may  be  separated  into  a  kind  of  lace.  The  berries  are  more  or 
less  deleterious. 

900.  Ord.  EleagMCese  (Oleaster  Family).  Shrubs  or  small  trees, 
with  the  flowers  more  commonly  dioecious ;  readily  distinguished 
from  the  preceding  by  having  the  foliage  and  shoots  covered  with 
scurf,  by  the  ascending  albuminous  seed,  and  the  persistent  tube  of 


FIG.  1118.    Flowering  branch  of  Dirca  palustris.     1119.  A  flower.     1120.  The  same,  laid 
open  and  enlarged.     1121.  Branch  in  fruit. 


468 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


the  calyx,  which,  although  free  from  the  ovary,  becomes  succulent, 
like  a  berry  in  fruit,  and  constricted  at  the  throat,  enclosing  the 
crustaceous  achenium.  —  Ex.  Eleagnus,  Shepherdia.  Plants  of  no 
economical  importance,  except  that  a  few  are  cultivated  for  their 
silvery  foliage.  The  fruit  is  sometimes  eaten,  as  is  that  of  the  Buf- 
falo-berry (Shepherdia  argentea)  and  Silver-berry  (Eleagnus  ar- 
gentea)  by  the  Northern  aborigines. 

901.  Ofd.  ProteaceEB  (Protect  Family).  A  rather  large  family  of 
shrubs  and  trees  of  Southern  temperate  and  subtropical  regions, 
chiefly  of  the  Cape  of  Good  Hope  and  Australia  (a  few  in  South 
America,  &c),  with  rigid  coriaceous  leaves,  perfect  flowers,  either 
regular  or  irregular,  mostly  in  heads  or  spikes  ;  the  lobes  of  the 
calyx  valvate  in  aestivation ;  a  stamen  borne  on  each  of  its  four 
lobes  ;  the  pistil  simple  and  free,  forming  a  mostly  dehiscent  fruit ; 
seeds  with  a  large  and  straight  embryo,  and  no  albumen.  Many 
of  these  plants  are  prized  in  conservatories  for  their  beauty  or  sin- 
gularity :  the  seeds  of  a  few  species  are  eaten. 

902.  Ord.  SantalaceSB  (Sandal-ivood  Family).  Trees,  shrubs,  or 
sometimes  herbs  (their  roots  inclined  to  form  parasitic  attach- 
ments) ;  with  alternate  entire  leaves,  and  small  (very  rarely  dioe- 


cious) flowers.  Calyx-tube  adherent  to  the  ovary ;  the  limb  four- 
or  five-cleft,  valvate  in  aestivation ;  its  base  lined  with  a  fleshy  disk, 
the  edge  of  which  is  often  lobed.     Stamens  as  many  as  the  lobes  of 


FIG.  1122.  Branch  of  Comandra  umbellata.  1123.  Enlarged  flower,  laid  open.  1124.  Ver- 
tical section  of  a  flower.  1125.  One  of  the  segments  of  the  calyx,  enlarged,  showing  the  tuft 
of  hairs  which  connects  its  surface  with  the  anther  !    1126.  The  fruit,  reduced  in  size. 


EXOGENOUS    OR   DICOTYLEDONOUS   PLANTS.  469 

the  calyx,  and  opposite  them,  inserted  on  the  edge  of  the  disk. 
Ovules  several,  destitute  of  proper  integuments,  pendulous  from  the 
apex  of  a  stipe-like  basilar  placenta.  Style  one.  Fruit  indehiscent, 
crowned  with  the  limb  of  the  calyx.  Seed  albuminous.  Embryo 
small.  —  Ex.  Comandra,  Pyrularia,  &c.  The  fragrant  Sandal-wood 
is  obtained  from  several  Indian  and  Polynesian  species  of  Santalum. 
The  large  seeds  of  Pyrularia  oleifera  (Buffalo-tree,  Oil-nut),  of  the 
Alleghany  Mountains,  would  yield  a  copious  fixed  oil.  One  species 
of  Fusanus  in  Australia  is  esteemed  for  its  edible  seeds,  known  by 
the  name  of  Quandang-nuts. 

903.  Ord.  LorantliaceCB  {Mistletoe  Family)  consists  of  shrubby 
plants,  with  articulated  branches,  and  opposite  coriaceous  and  mostly 
dull  greenish  entire  leaves  ;  parasitic  on  trees.  The  floral  envelopes 
are  various.  In  Mistletoe  (which  is  dioecious)  the  anthers  are  ses- 
sile and  adnate  to  the  face  of  the  sepals,  one  to  each ;  while  Lo- 
ranthus  has  both  calyx  and  corolla,  the  latter  most  conspicuous,  and 
a  stamen  before  each  petal  and  adnate  to  it.  The  ovary  is  one- 
celled,  with  a  single  suspended  ovule,  consisting  of  a  nucleus  without 
integuments.  Fruit  a  one-seeded  berry.  Embryo  small,  in  fleshy 
albumen.  —  Ex.  Loranthus  ;  Viscum,  the  Mistletoe,  from  the  glu- 
tinous berries  of  which  birdlime  is  made  ;  Phoradendron,  the  Ameri- 
can Mistletoe.     The  bark  is  astringent. 

904.  Ord.  Piperacea;  {Pepper  Family).  A  peculiar  order  of  tropical 
herbaceous  or  shrubby  plants,  with  jointed  stems,  naked  (achlamyde- 
ous)  but  perfect  flowers  in  spikes  or  spicate  racemes,  a  one-celled  ovary 
with  an  erect  orthotropous  ovule ;  the  embryo  minute  in  a  vitellus 
or  persistent  embryo-sac  at  the  apex  of  the  albumen.  —  Pungent 
and  stimulant  properties  characterize  the  order.  Piper  nigrum  fur- 
nishes Black  pepper,  and  Wliite  pepper  is  the  same,  with  the  flesh  of 
the  drupe  removed.  The  fruit  of  Cubeba  officinalis,  &c.  furnishes 
Cubebs,  Avhich  are  hot  aromatics,  acting  also  on  the  mucous  mem- 
branes. The  pungency  in  all  these  plants  is  owing  to  a  peculiar 
volatile  oil  and  resin.  They  also  yield  a  crystalline  matter,  called 
Piperine.  Others  have  more  intoxicating  properties,  as  Betel,  the 
leaves  of  a  Chavica,  chewed  by  the  Malays,  and  the  Ava  (Macropi- 
per  methysticum)  from  which  the  South-Sea  Islanders  make  their 
inebriating  drink. 

905.  Ord.  SaururaceSB  {LizaroVs-tail  Family)  ;  differs  from  the  Pep- 
per Family  (of  which  it  is  an  offshoot)  in  the  feebly  pungent  quali- 
ties, the  distinct  stipules  (when  these  are  evident),  and  the  three  or 

40 


470 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


more  ovaries,  separate  or  somewhat  united,  with  one  or  more  ovules 
in  each.  —  Ex.  Saururus,  Hottuynia  :  a  small  group. 


906.  Ord.  Ceratopliyllacece  (Hornwort  Family)  consists  of  the  single 
genus  Ceratophyllum  (growing  in  ponds  and  streams  in  many  parts 
of  the  world)  ;  distinguished  hy  the  whorled  and  dissected  leaves 
with  filiform  segments ;  the  flowers  monoecious  and  sessile  in  the 
axil  of  the  leaves  ;  the  stamens  indefinite,  with  sessile  anthers  ;  and 
the  simple  one-celled  ovary,  which  forms  a  beaked  achenium  in  fruit, 
containing  an  orthotropous  suspended  seed,  with  four  cotyledons ! 
and  a  manifest  plumule. 

007.  Ord.  CallitrichaceSB  ( Water-Starwort  Family),  formed  of  the 
genus  Callitriche ;  aquatic  annuals,  with  opposite  entire  leaves ;  the 
axillary  flowers   (either  perfect  or  monoecious)  with  a  two-leaved 

FIG.  1127.  Saururus  cernuus.  1128.  A  separate  flower,  with  its  tract  and  a  part  of  the 
axis  magnified.  1129.  A  more  magnified  anther,  discharging  its  pollen  from  one  cell.  1130. 
Cross-section  of  the  ovary.  1131.  Vertical  section  of  one  of  the  carpels  in  fruit,  and  of  the 
contained  seed,  with  the  sac  at  the  extremity  of  the  albumen,  containing  the  minute  embryo. 
1132.  A  seed.  1133.  Same,  with  the  outer  integument  (testa)  removed,  showing  the  vitellus. 
1134.  The  latter,  highly  magnified.  1135.  Section  of  the  same,  showing  the  enclosed  heart- 
shaped  embryo. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


471 


involucre,  but  entirely  destitute  of  calyx  and  corolla ;  stamen  one 
(or  rarely  two),  hypogynous,  with  a  slender  filament,  and  a  reni- 
form  confluently  one-celled  anther ;  the  ovary  four-lobed,  four-celled, 
indehiscent  in  fruit ;  the  seeds  albuminous. 


908.  Ord.  Podostemaceae  (River-weed  Family)  comprises  a  few 
(chiefly  American  and  Asiatic)  aquatics,  in  rivers,  with  the  aspect 
of  Mosses,  Hepaticse,  &c. ;  their  small  flowers  arising  from  a  spathe  ; 
the  calyx  often  entirely  wanting  ;  the  stamens  frequently  unilateral 
and  monadelphous ;  the  ovary  two-  or  three-celled,  with  distinct 
styles  ;  in  fruit  forming  a  ribbed  capsule,  containing  numerous  ex- 
albuminous  seeds  attached  to  a  central  column.  —  Ex.  Podostemon. 

909.  Ord.  EupllorbiaceBB  {Spurge  Family).  Herbs,  shrubs,  or 
trees,  often  with  a  milky  juice  :  in  northern  temperate  climes  chiefly 
represented  by  the  genus  Euphorbia  ;  which  is  remarkable  for  hav- 
ing numerous  staminate  flowers,  reduced  to  a  single  stamen  (487), 
enclosed  in  an  involucre  along  with  one  pistillate  flower,  this  reduced 
to  a  compound  pistil,  and  also  achlamydeous,  or  with  an  obsolete 
calyx.  But  other  genera  have  a  regular  calyx  both  to  the  staminate 
and  pistillate  flowers  ;  and  a  few  are  likewise  provided  with  petals. 
Ovary  of  two  to  nine  more  or  less  united  carpels,  coherent  to  a  cen- 
tral prolongation  of  the  axis  :  styles  distinct,  often  two-cleft.  Fruit 
mostly  capsular,  separating  into  its  elementary  carpels,  or  cocci 
(usually  leaving  a  persistent  axis)  :  these  commonly  open  elastically 

FIG.  1136.  Callitriche  verna,  about  the  natural  size.  1137.  Perfect  flowers,  magnified. 
1138.  A  staminate  and  pistillate  flower,  magnified.  1139.  The  fruit.  1140.  Cross-section  of 
the  fruit.    1141.  Vertical  section  through  the  pericarp,  seeds,  and  embryo. 


472 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


by  one  or  both  sutures.  Seed  with  a  large  embryo  in  fleshy  albu- 
men, suspended.  —  Ex.  Euphorbia  (Spurge),  Croton,  Buxus  (the 
Box).     Acrid  and  deleterious  qualities  pervade  this  large  order, 


chiefly  resident  in  the  milky  juice.  But  the  starchy  accumulations 
in  the  rhizoma,  or  underground  portion  of  the  stem,  as  in  the  Man- 
dioc  or  Cassava  (Janipha  Manihot)  of  tropical  America,  are  per- 
fectly innocuous,  when  freed  from  the  poisonous  juice  by  washing 
and  heating.  The  starch  thus  obtained  is  the  Cassava,  which,  when 
granulated,  forms  the  Tapioca  of  commerce.  The  farinaceous  albu- 
men of  the  seed  is  also  innocent,  and  the  fixed  oil  which  it  frequently 
contains  is  perfectly  bland.  But  the  oil  procured  by  expression 
abounds  in  the  juices  of  the  embryo  and  integuments  of  the  seed,  and 
possesses  more  or  less  active  properties.  The  seeds  of  Ricinus  com- 
munis yield  the  Castor  oil :  and  those  of  Croton  Tiglium,  and  some 
other  Indian  species,  yield  the  violently  drastic  Croton  oil  or  Oil  of 

FIG.  1142.  Flowering  branch  of  Euphorbia  corollata ;  the  lobes  of  the  involucre  resem- 
bling a  corolla.  1143.  Vertical  section  of  an  involucre  (somewhat  enlarged),  showing  a  portion 
of  the  staminate  flowers  surrounding  the  pistillate  flower  (a),  which  in  fruit  is  raised  on  a 
slender  pedicel.  1144.  One  of  the  staminate  flowers  enlarged,  with  its  bract,  a :  b,  the  pedicel, 
to  which  the  single  stamen,  c,  is  attached  by  a  joint ;  there  being  no  trace  of  floral  envelopes. 
1145.  Cross-section  of  the  3-pistillate  fruit.  1146.  Vertical  section  of  one  of  the  pistils  in  fruit 
(the  two  others  having  fallen  away  from  the  axis),  and  of  the  contained  seed ;  showing  the  em- 
bryo lengthwise.    1147.  A  seed. 


EXOGENOUS    Oil    DICOTYLEDONOUS    PLANTS. 


473 


Tiglium.  Some  plants  of  the  family  are  most  virulent  poisons  ;  as, 
for  example,  the  Manchineal-tree  of  the  West  Indies  (Hippomane 
Manicella),  which  is  said  even  to  destroy  persons  who  sleep  under  its 
shade  ;  and  a  drop  of  the  juice  blisters  the  hand.  The  hairs  of  some 
sj>ecies  (such  as  our  Cnidoscolus  stimulosus)  sting  like  Nettles.  Box- 
wood is  invaluable  to  the  wood-engraver.  The  purple  dye  called 
Turnsole  is  from  Crozophora  tinctoria.  Another  most  important 
product  of  this  order  is  Caoutchouc,  which  is  yielded  by  various  plants 
of  different  families ;  but  the  principal  supply  of  the  article  (that  of 
Para,  Demarara,  and  Surinam)  is  furnished  by  species  of  Siphonia. 
910.  Ord.  EmpetracCBB  {Crowberry  Family).  Low,  shrubby  ever- 
greens, with  the  aspect  of  Heaths ;  the  leaves  crowded  and  acerose, 


with  small  (dioecious  or  polygamous)  flowers  produced  in  the  axils. 
Calyx  consisting  of  regular  imbricated  sepals,  or  represented  by  im- 
bricated bracts.  Stamens  few  :  pollen  of  four  grains  coherent  in 
one,  as  in  Heath.  Ovaiy  three-  to  nine-celled,  with  a  single  erect 
ovule  in  each  cell :  style  short  or  none  :  stigmas  lobed  and  often 
laciniated.  Fruit  a  drupe,  with  from  three  to  nine  bony  nucules. 
Seeds  albuminous ;  the  radicle  inferior.  —  Ex.  Empetrum,  Ceratiola, 
Corema;  unimportant  plants.  Probably  no  more  than  apetalous 
Ericaceae  ;  but  the  stigmas  are  peculiar. 

911.  Ord.  UrticaceSB  {Nettle  Family),  shrubs,  or  herbs,  with  stipules, 
often  with  milky  juice,  and  diclinous  or  polygamous,  rarely  perfect 
flowers,  furnished  with  a  regular  calyx ;  which  is  free  from  the  one- 

FIG.  1148.  Branch  of  Ceratiola  ericoides  in  fruit.  1149.  Magnified  staminate  flower,  with 
its  bracts.  1150.  The  two  stamens,  with  an  inner  bract  or  sepal.  1151.  Magnified  pistillate 
flower,  with  its  imbricated  bracts.  1152.  The  pistil  separate ;  one  of  the  cells  laid  open  by  a 
vertical  section,  showing  the  erect  ovule.    1153.  Drupe,  with  the  persistent  scales  at  the  base. 

1154.  Transverse  section  of  its  endocarp,  or  two  nucules,  with  the  enclosed  seed  and  embryo. 

1155.  Vertical  section  of  the  seed. 

40* 


474 


ILLUSTRATIONS    OP    THE    NATURAL    ORDERS. 


celled  (sometimes  two-celled)  ovary  and  the  always  one-celled  and 
one-seeded  fruit,  but  sometimes  enclosing  it.  Stamens  as  many  as 
the  lobes  of  the  calyx  and  opposite  them,  or  sometimes  fewer.  Em- 
bryo large  ;  cotyledons  mostly  broad ;  the  radicle  superior  in  the 
fruit.  Stipules  often  deciduous.  A  large  and  greatly  diversified 
order,  comprising  at  least  four  well-marked  suborders. 

912.  Suboi'd.  UimaceSB  (Elm  Family).  Trees  or  shrubs,  with  a 
watery  juice,  alternate  rough  leaves,  perfect  or  merely  polygamous 
flowers,  two  styles  or  stigmas  ;  the  ovary  either  one-  or  two-celled, 
with  one  ovule  suspended  from  the  summit  of  each.  Fruit  either  a 
samara  (Fig.  578),  with  a  straight  embryo  and  no  albumen,  as  in 


^m  ^»£| 


m^ 


<7 


the  Elm  (Uhnus)  ;  or  a  drupe  with  a  curved  embryo  and  scanty 
albumen,  as  in  Celtis  (Hackberry),  the  type  of  the  tribe  Celtide^e. 
Timber-trees.  The  inner  bark  of  the  Slippery  Elm  is  highly 
charged  with  mucilage.     Hackberries  are  edible. 

913.  Subord.  ArtocarpeSB  (Bread-fruit  Family) ;  which  are  chiefly 
tropical  trees  or  shrubs  with  a  milky  or  yellow  juice ;  the  monoe- 
cious or  dioecious  flowers  mostly  aggregated  into  fleshy  heads,  and 


FIG.  1156.  Flower  of  the  Slippery  Elm.  1157.  Calyx  laid  open  and  the  ovary  divided  ver- 
tically. 1158.  Fruit,  the  cell  laid  open  to  show  the  single  seed.  1159.  The  latter  magnified. 
1160.  Its  embryo. 

FIG.  1161.  Branch  of  Celtis  Americana,  in  flower.  1162.  Enlarged  flower,  divided  verti- 
cally.    1163.  Drupe,  the  flesh  divided  to  show  the  stone.     1163'.  The  coiled  embryo. 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS.  475 

forming  a  multiple  fruit,  or  else  enclosed  in  a  dry  or  succulent  invo- 
lucre. Styles  or  stigmas  commonly  two.  Ovary  ripening  into  an 
achenium.  Seeds  with  or  without  albumen.  —  Ex.  Artocarpus  (the 
Bread-fruit),  Morus  (the  Mulberry,  Fig.  593-595),  Madura  (the 
Osage  Orange),  Ficus  (the  Fig,  Fig.  590-592).  The  fruit  is 
often  innocent  and  edible,  at  least  when  cooked ;  while  the  milky 
juice  is  more  or  less  acrid  or  deleterious.  It  also  abounds  in  Caout- 
chouc. ;  much  of  which  is  obtained  from  some  South  American  trees  of 
this  order,  and  from  Fiscus  elastica  in  Java.  In  one  instance,  how- 
ever, the  milky  juice  is  perfectly  innocent ;  that  of  the  famous  Cow- 
tree  of  South  America,  which  yields  a  rich  and  wholesome  milk. 
One  of  the  most  virulent  of  poisons,  the  Bohon  Lpas,  is  the  concrete 
juice  of  Antiaris  toxicaria  of  the  Indian  Archipelago.  The  Bread- 
fruit is  the  fleshy  receptacle  and  multiple  fruit  of  Artocarpus. 
Fustic  is  the  wood  of  the  South  American  Madura  tinctoria ;  the 
wood  of  our  own  Madura  or  Osage  Orange  is  used  by  the  "Western 
Indians  for  bows.  The  resin  called  Gttm  Lac  exudes  and  forms 
small  grains  on  the  branches  of  the  celebrated  Banyan-tree  (Ficus 
Indica,  Fig.  142). 

914.  SubOl'd.  UrticeSB  (True  Nettle  Family)  ;  which  are  herbs  in 
colder  countries,  but  often  shrubs  or  trees  in  the  tropics,  with  a 
watery  juice,  often  with  stinging  hairs ;  the  monoecious  or  dioecious 
flowers  mostly  loose,  spicate,  or  panicled.  Ovule  orthotropous. 
Ovary  always  one-celled,  and  style  or  stigma  one  ;  the  achenium 
usually  surrounded  by  a  dry  and  membranous  calyx.  Embryo 
straight,  in  fleshy  albumen.  —  Ex.  Urtica  (the  Nettle),  &c.  Innoc- 
uous plants,  except  for  the  stinging  hairs  of  many  species.  The 
inner  bark  of  Nettles  yields  very  tough  and  slender  fibres. 

915.  Subord.  CannabillCSD  (Hemp  Family).  Annual  erect  herbs, 
or  perennial  twining  plants,  with  a  watery  juice  and  dioecious  flow- 
ers ;  the  staminate  flowers  racemose  or  panicled ;  the  pistillate  glom- 
erate, or  imbricated  with  bracts,  and  forming  a  kind  of  strobile-like 
anient ;  their  calyx  one-leaved.  Stigmas  two.  Ovary  one-celled, 
with  an  erect  orthotropous  ovule.  Embryo  coiled  or  bent :  albumen 
none.  —  Ex.  Cannabis  (the  Hemp),  Humulus  (the  Hop).  Hops 
are  the  catkins  with  large  bracts ;  the  bitter  and  sedative  principle 
chiefly  resides  in  the  yellow  grains  that  cohere  to  the  scales  and 
cover  the  fruit.  The  leaves  of  Hemp,  when  grown  in  a  hot  climate, 
are  powerfully  stimulant  and  narcotic,  and  are  used  in  the  East  for 
intoxication.     The  inner  bark  is  used  for  cordage,  &c. 


476  ILLUSTRATIONS    OF    THE   NATURAL    ORDERS. 

916.  Ord.  Plataiiacesc  (Plane-tree  Family)  consists  of  the  single 
genus  Platanus  (Plane-tree,  Button-ball),  with  one  Asiatic  and  one 
or  more  North- American  species :  fine  trees,  with  a  watery  juice, 
and  alternate  palmately-lobed  leaves,  with  sheathing  stipules.  Flow- 
ers in  globose  amentaceous  heads  ;  both  kinds  destitute  of  floral 
envelopes.  Fruit  a  one-seeded  club-shaped  little  nut,  the  base  fur- 
nished with  bristly  hairs.     Seed  albuminous. 

917.  Ord.  JllglaildaceEE  {Walnut  Family).  Trees,  with  alternate 
pinnated  leaves,  and  no  stipules.  Flowers  monoecious.  Sterile 
flowers  in  aments,  with  a  membranous  irregular  calyx,  and  indefinite 
stamens.  Fertile  flowers  few,  clustered,  with  the  calyx  adherent  to 
the  incompletely  two-  to  four-celled  but  one-ovuled  ovary,  the  limb 
small,  three-  to  five-parted ;  sometimes  with  as  many  small  petals. 
Ovule  orthotropous.  Fruit  drupaceous ;  the  exocarp  fibrous-fleshy 
and  coherent,  or  else  coriaceous  and  dehiscent :  endocarp  bony. 
Seed  four-lobed,  without  albumen.  Embryo  oily :  cotyledons  cor- 
rugate, two-cleft.  —  Ex.  Juglans  (Walnut,  Butternut),  Carya  (Hick- 
ory, Pecan,  &c).  —  The  greater  part  of  the  order  is  North  Ameri- 
can. The  timber  is  valuable  ;  especially  that  of  Black  Walnut, 
for  cabinet-work,  and  that  of  Hickory,  for  its  great  elasticity  and 
strength.  The  young  fruit  is  acrid :  the  seeds  of  several  are  de- 
licious ;  those  of  the  Walnut  abound  in  a  drying  oil. 

918.  Ol'd.  CupilliferSB  {Oak  Family).  Trees  or  shrubs,  with  alter- 
nate and  simple  straight-veined  leaves,  and  deciduous  stipules. 
Flowers  usually  monoecious.  Sterile  flowers  in  aments,  with  a 
scale-like  or  regular  calyx,  and  the  stamens  one  to  three  times  the 
number  of  its  lobes.  Fertile  flowers  solitary,  two  to  three  together, 
or  in  clusters,  furnished  with  an  involucre  which  encloses  the  fruit 
or  forms  a  cupule  at  its  base.  Ovary  adnate  to  the  calyx,  and 
crowned  by  its  minute  or  obsolete  limb,  two-  to  six-celled  with  one 
or  two  pendulous  ovules  in  each  cell :  but  the  fruit  is  a  one-celled 
and  one-seeded  nut  (Fig.  576).  Seed  without  albumen.  Embryo 
with  thick  and  fleshy  cotyledons,  which  are  sometimes  coalescent.  — 
Ex.  Quercus  (the  Oak),  Fagus  (the  Beech),  Corylus  (the  Hazel- 
nut), Castanea  (the  Chestnut),  &c.  Some  of  the  principal  forest- 
trees  in  northern  temperate  regions.  The  valuable  timber  and 
edible  nuts  they  furnish  are  too  well  known  to  need  enumeration. 
The  astringent  bark  and  leaves  of  the  Oak  abound  in  tannin,  gallic 
acid,  and  a  bitter  extractive  called  Quercine  ;  they  are  used  in  tan- 
ning and  dyeing.      Quercitron  is  obtained  from  the  Quercus  tine- 


EXOGENOUS    OR   DICOTYLEDONOUS    PLANTS. 


477 


toria.  Galls  are  swellings  on  the  leafstalks,  &c.,  when  wounded  hy 
certain  insects  ;  those  of  commerce  are  derived  from  Q.  infectoria  of 
Asia  Minor.  Cork  is  the  exterior  corky  layer  of  the  bark  of  the 
Spanish  Quercus  Suber. 


919.  Ord.  Myricacece  (Sweet- Gale  Family).  Shrubs,  with  alter- 
nate and  simple  aromatic  resinous-dotted  leaves,  monoecious  or  dioe- 
cious. Differs  from  the  next  principally  by  the  one-celled  ovary, 
with  a  single  erect  orthotropous  ovule,  and  a  drupe-like  nut.  —  Ex. 
Myrica,  Comptonia,  the  Sweet  Fern.  The  drupes  of  M.  cerifera 
(our  Candleberry  or  Bayberry)  yield  a  natural  wax. 

920.  Ol'd.  BetlllaceSB  (Birch  Family).  Trees  or  shrubs,  with  al- 
ternate and  simple  straight-veined  leaves,  and  deciduous  stipules. 
Flowers  monoecious  ;  those  of  both  kinds  in  aments  (Fig.  312),  and 
commonly  achlamydeous,  placed  three  together  in  the  axil  of  each 
three-lobed  bract.  Stamens  definite.  Ovary  two-celled,  each  cell 
with  one  suspended  ovule :  styles  or  stigmas  distinct.  Fruit  mem- 
branaceous or  samara-like,  one-celled  and  one-seeded,  forming  with 
the  three-lobed  bracts  a  kind  of  strobile.  Albumen  none.  —  Ex. 
Betula  (the  Birch),  Alnus  (Alder).     The  bark  is  sometimes  astrin- 

FIG.  1164.  Quercus  Chinquapin  in  fruit :  a,  cluster  of  sterile  aments.  1165.  A  magnified 
Btaminate  flower.  1166.  Transverse  section  of  an  ovary,  showing  the  three  cells  with  two 
ovules  in  each.  1167.  The  immature  seed,  with  the  accompanying  abortive  ovule.  1168.  The 
nut  (acorn),  in  its  scaly  involucre,  or  cupule.  1169.  Vertical  section  of  the  same,  and  of  the 
included  seed  and  embryo,  showing  the  thick  cotyledons. 


478 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


gent,  and  that  of  the  Birch  is  aromatic.  The  peculiar  odor  of 
Russia  leather  is  said  to  be  owing  to  a  pyroligneous  oil  obtained 
from  Betula  alba,  or  White  Birch. 


921.  Ol'd.  SalicaceOB  (Willow  Family).  Trees  or  shrubs,  with  al- 
ternate simple  leaves,  furnished  with  stipules.  Flowers  dioecious  ; 
both  kinds  in  aments,  and  destitute  of  floral  envelopes  (achlamyde- 
ous),  one  under  each  bract.  Stamens  two  to  several,  sometimes 
monadelphous.  Ovary  one-celled,  many-ovuled  !  Styles  or  stigmas 
two,  often  two-cleft.  Fruit  a  kind  of  follicle  opening  by  two  valves. 
Seeds  numerous,  ascending,  furnished  with  a  silky  coma !  Albu- 
men none.  —  Ex.  Salix  (Willow,  Fig.  415-419),  and  Populus  (the 
Poplar).  Trees  with  light  and  soft  wood  :  the  slender,  flexible 
shoots  of  several  Willows  are  employed  for  wicker-work.  The  bark 
is  bitter  and  tonic,  and  contains  a  peculiar  substance  (Salicine), 
which  possesses  febrifugal  qualities.  The  buds  of  several  Poplars 
exude  a  fragrant  balsamic  resin. 

FIG.  1170.  Young  ament  of  staminate  flowers  of  a  Birch  (Betulafruticosa?).  1171.  One  of 
the  three-lobed  scales  of  the  same,  enlarged,  showing  the  flowers  (stamens)  on  the  inner  side. 
1172.  Ament  of  pistillate  flowers.  1173.  Branch  in  fruit.  1173'.  One  of  the  scales  with  its 
three  flowers  (pistils)  seen  from  within.  1174.  Magnified  section  of  one  of  the  two-celled  pis- 
tils, displaying  the  ovule  suspended  from  the  summit  of  each  cell.  1175.  The  pistils  (with 
their  subtending  bract)  in  a  more  advanced  state.  1176.  Magnified  cross-section  of  one  of  the 
ovaries.  1177.  The  mature  fruit,  with  the  cell  divided  vertically  ;  the  single  seed  occupying 
the  cavity  ;  a  mere  trace  of  the  other  cell  being  visible.  1178.  The  seed  removed.  1179.  The 
embryo. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


479 


Subclass  2.     Gymnospermous  Exogenous  Plants. 

Ovules,  and  consequently  the  seeds,  naked,  that  is,  not  enclosed  in 
an  ovary  (560)  ;  the  carpel  being  represented  either  by  an  open 
scale,  as  in  Pines  ;  or  by  a  more  evident  leaf,  as  in  Cycas  ;  or  else 
wanting  altogether,  as  in  the  Yew. 

922.  Ol'd.  ConiferSC  {Pine  Family).  Trees  or  shrubs,  with  branch- 
ing trunks,  abounding  in  resinous  juice  (the  wood  chiefly  consisting 
of  a  tissue  somewhat  intermediate  between  ordinary  woody  fibre 
and  vessels,  and  marked  with  circular  disks)  ;  the  leaves  mostly 


evergreen,  scattered  or  fascicled,  usually  rigid  and  needle-shaped  or 


FIG.  1180.  Carpellary  scale  of  Cupressus  sempervirens  (the  true  Cypress),  seen  from  with- 
in, and  showing  the  numerous  orthotropous  ovules  that  stand  on  its  hase.  1181.  Branch  of 
Abies  Canadensis  (Hemlock  Spruce),  with  lateral  staminate  flowers,  and  a  fertile  strobile. 
1182.  Staminate  anient,  magnified.  1183.  Carpellary  scale  of  a  fertile  anient,  with  its  bract. 
1184.  Similar  fertile  scale,  more  magnified  and  seen  from  within ;  showing  the  two  ovules  ad- 
herent to  its  base:  one  of  them  (the  left)  laid  open.  1185.  The  scale  in  front,  nearly  of  the 
natural  size,  its  inner  surface  occupied  by  the  two  seeds.  1186.  Polycotyledonous  embryos  of 
Abies  and  Cypress.  1187.  Vertical  section  of  an  embryo.  1188.  Strobile  of  Taxodium  dis- 
tichum  (Suborder  Cupressineae). 


480  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

linear,  entire.  Flowers  monoecious  or  dioecious,  commonly  amenta- 
ceous. Staminate  flowers  consisting  of  one  or  more  (often  mona- 
delphous)  stamens,  destitute  of  calyx  or  corolla,  ai*ranged  on  a  com- 
mon rhachis  so  as  to  form  a  kind  of  loose  anient.  —  The  particular 
structure  of  the  flowers  and  fruit  varies  in  the  subordinate  groups, 
chiefly  as  follows  :  — 

923.  Sllboril.  AbietineBB  {Fir,  or  Pine  Family  proper).  Fertile 
aments  formed  of  imbricated  scales  ;  which  are  the  flat  and  open 
carpels,  and  bear  a  pair  of  ovules  adherent  to  their  base,  with  the 
foramen  turned  downwards  (Fig.  511).  Scales  subtended  by  bracts. 
Fruit  a  strobile  or  cone  (Fig.  596).  Integument  of  the  seed  cori- 
aceous or  woody,  more  or  less  firmly  adherent  to  the  scale.  Em- 
bryo in  the  axis  of  fleshy  albumen,  with  two  to  fifteen  cotyledons. 
Buds  scaly. 

924.  Sllboril.  ClipressineOB  {Cypress  Family).  Fertile  aments  of 
few  scales  crowded  on  a  short  axis,  or  more  numerous  and  peltate, 
not  bracteate.  Ovules  one,  two,  or  several,  borne  on  the  base  of  the 
scale,  erect  (the  foramen  looking  towards  its  apex,  Fig.  516,  1180). 
Fruit  an  indurated  strobile,  or  sometimes  fleshy  and  with  the  scales 
concreted,  forming  a  kind  of  drupe.  Integument  of  the  seed  mem- 
branous or  bony.  Cotyledons  two  or  more.  Anthers  of  several 
parallel  cells,  placed  under  a  shield-like  connective.  Buds  naked. 
—  Ex.  Cupressus  (Cypress),  Taxodium  (American  Cypress),  Juni- 
perus  (Juniper,  Bed  Cedar). 

925.  Sllbord.  Taxilieae  (Yeto  Family).  Fertile  flowers  solitary, 
terminal,  consisting  merely  of  an  ovule,  forming  a  drupaceous  or  nut- 
like seed  at  maturity.  There  are,  therefore,  no  strobiles  and  no 
carpellary  scales.  Embryo  with  two  cotyledons.  Buds  scaly.  — 
Ex.  Taxus  (the  Yew),  Torreya. 

926.  It  is  unnecessary  to  specify  the  important  uses  of  this  large 
and  characteristic  family,  which  comprises  the  most  important  tim- 
ber-trees of  cold  countries,  and  also  furnishes  resinous  products  of 
great  importance,  such  as  turpentine,  resin,  pitch,  tar,  Canada  bal- 
sam, &c.  The  terebinthine  Juniper-berries  are  the  fruit  of  Juni- 
perus  communis.  The  Larch  yields  Venetian  turpentine.  The 
powerful  and  rubefacient  Oil  of  Savin  is  derived  from  J.  Sabina  of 
Europe  :  for  which  our  nearly  allied  J.  Virginiana  (Bed  Cedar) 
may  be  substituted.  The  leaves  of  the  Yew  are  narcotic  and  dele- 
terious. The  bark  of  Larch,  and  especially  of  the  Hemlock-Spruce, 
is  used  for  tanning. 


EXOGENOUS    OR    DICOTYLEDONOUS    PLANTS. 


481 


927.  Ord.  CycadaccCB  {Cycas  Family).  Tropical  plants,  with  an 
unbranched  cylindrical  trunk,  increasing,  like  Palms,  by  a  single 
terminal  bud ;  the  leaves  pinnate  and  their  segments  more  or  less 
rolled  up  from  the  apex  (circulate)  in  vernation,  in  the  manner  of 
Ferns.  Flowers  dioecious  ;  the  staminate  in  a  strobile  or  cone  ;  the 
pistillate  also  in  strobiles,  or  else  (in  Cycas)  occupying  contracted 


and  partly  metamorphosed  leaves  ;  the  naked  ovules  borne  on  its 
margins.  —  Ex.  Cycas,  Zamia.  —  A  kind  of  Arroioroot  is  obtained 
from  these  thickened  stems,  or  caudexes,  as  from  our  dwarf  Florida 
species  (the  Coontie  of  the  aborigines)  ;  and  a  coarse  Sago  from 
the  trunk  of  Cycas. 

FIG.  1189.  Zamia  integrifolia  (the  Coontie  of  Florida).  1190.  Section  of  the  sterile  ament. 
1191.  One  of  its  scales  detached,  bearing  scattered  anthers.  1192.  Fertile  anient,  from  which 
a  quarter-section  is  removed.  1193.  A  pistillate  flower,  consisting  of  two  ovules  pendent  from 
the  thickened  summit  of  the  carpellary  scale.  1194.  A  drupaceous  seed,  from  which  a  part  of 
the  pulpy  outer  portion,  at  the  apex,  is  removed.  1195.  Vertical  section  through  the  seed  (of 
the  natural  size),  showing  the  pulpy  outer  coat,  the  hard  inner  integument,  the  albumen,  and 
the  embryo. 


41 


482  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


Class  II.     Endogenous  or  Monocotyledonous  Plants. 

Stem  not  distinguishable  into  bark,  pith,  and  wood  ;  but  the  latter 
consisting  of  bundles  of  fibres  and  vessels  irregularly  imbeded  in 
cellular  tissue ;  the  rind  firmly  adherent ;  no  medullary  rays,  and 
no  appearance  of  concentric  layers  :  increase  in  diameter  effected 
by  the  deposition  of  new  fibrous  bundles,  which  at  their  commence- 
ment occupy  the  central  part  of  the  stem.  Leaves  seldom  falling 
off  by  an  articulation,  sheathing  at  the  base,  usually  alternate,  entire, 
and  with  simple  parallel  veins  (nerved).  Floral  envelopes  when 
present  mostly  in  threes,  never  in  fives  ;  the  calyx  and  corolla  most 
commonly  undistinguishable  in  texture  and  appearance.  Embryo 
with  a  single  cotyledon  ;  or,  if  the  second  is  present,  it  is  much 
smaller  than  the  other,  and  alternate  with  it. 

Conspectus  of  the  Orders. 

Group  1.  Flowers  on  a  spadix,  furnished  with  a  double  and  free  perianth 
(answering  to  calyx  and  corolla).  Ovary  one-  to  three-celled,  with  a  single 
ovule  in  each  cell.  Embryo  in  hard  albumen. —  Trees  with  unbranched 
columnar  trunks.  Palm^e. 

Group  2.  Flowers  on  a  spadix  ;  with  the  perianth  simple  and  free,  or  reduced 
to  a  few  scales,  or  commonly  altogether  wanting.  —  Cbiefly  herbs. 

Terrestrial.     Fruit  nut-like,  or  comose,  one-seeded.  Typhace^e. 

Terrestrial,  mostly  with  a  spathe.  Fruit  baccate.  Arace^;. 
Aquatic  (floating  or  immersed). 

Flowers  developed  from  the  edge  of  the  floating  frond.  LemnacevE. 

Flowers  axillary  or  on  a  spadix.  Naiadace>e. 

Group  3.  Flowers  not  spadiceous,  furnished  with  a  double  and  free  perianth 
(calyx  and  corolla).  Ovaries  several,  distinct,  or  sometimes  united.  Aquat- 
ic herbs.  Alismace2E. 

Group  4.  Flowers  with  a  simple  or  doable  perianth,  which  is  adherent  to  the 
ovary,  regular,  developed  from  a  spathe,  polygamous  or  diclinous.  Ovary 
one-celled  with  parietal  placenta?,  or  3  -  9-celled.  Seeds  destitute  of  albu- 
men. —  Aquatics.  Hydrocharidace;e. 

Group  5.  Flowers  perfect  with  the  double  or  6-merous  perianth  adherent  to  the 
ovary  (or  more  or  less  free  in  some  Hamiodoracea;  and  Bromeliacea;). 
Seeds  with  albumen,  except  perhaps  the  very  minute  ones  of  Orchidacere, 
&c.    Leaves  parallel-veined. 


ENDOGENOUS  OR  MONOCOTYLEDONOUS  PLANTS.     483 

Stamens  gynandrous,  1  or  2  fertile.    Flower  irregular.  Orchidace^e. 

Stamens  not  gynandrous.     Flower  irregular. 
Fertile  stamen  I,  inferior.  Zingii!Erace^;. 

Fertile  stamen  1,  superior.  Cannace^e. 

Fertile  stamens  mostly  5,  the  sixth  abortive.  Musaceje. 

Stamens  not  gynandrous,  regularly  3  or  6. 
Anthers  extrorse.     Stamens  3,  before  the  sepals.  Iridace;e. 

Anthers  introrse,  when  3  before  the  inner  perianth. 

Anther-cells  separated  by  a  broad  connective.  Burmanniace;e. 

Anther-cells  approximate  or  joined. 

Leaves  not  scurfy.     Stems  from  bulbs.  Amaryllidace^e. 

Leaves  scurfy  or  woolly.    No  bulbs. 

Terrestrial.     Stamens  3  or  6.  Hjemodoracejs. 

Mostly  epiphytes.     Stamens  6.  Bromeliace.e. 

Group  6.  Flowers  dioecious,  with  a  6-merous  perianth  adherent  to  the  ovary. 
Seeds  with  a  minute  embryo  in  hard  albumen.  Leaves  ribbed  and  netted- 
veined,  articulated  with  the  stem.  Dioscoreace^e. 

Group  7.  Flowers  dioecious  or  perfect ;  the  regular  perianth  free  from  the  ovary. 
Styles  or  sessile  stigmas  distinct.  Embryo  minute  in  hard  albumen. 
Leaves  more  or  less  netted-veined.  Smilace;e. 

Group  8.     Flowers  perfect,  not  from  a  spathe,  with  the  regular  6-merous  peri- 
anth free  from  the  ovary.     Seeds  anatropous,  with  albumen. 
Perianth  not  glumaceous.     Leaves  parallel-veined. 

Anthers  introrse.     Styles  united  into  one.  Liliace^e. 

Anthers  extrorse.     Styles  mostly  separate.  Melanthace.e. 

Perianth  glumaceous.     Styles  united  into  one.  Juncace^;. 

Group  9.  Flowers  perfect,  developed  from  a  spathe,  commonly  somewhat  ir- 
regular, the  6-merous  perianth  free  from  the  ovary.  Seeds  anatropous,  with 
albumen.     Aquatics.  Pontederiace-E. 

Group  10.  Flowers  with  a  double  or  imbricated  perianth,  free  from  the  ovary  ; 
the  exterior  divisions  (sepals)  herbaceous  or  glumaceous  ;  the  inner  (pet- 
als) petaloid,  free  from  the  one-  to  three-celled  ovary.  Seeds  2,  3,  or  many, 
orthotropous  ;  the  embryo  at  the  extremity  of  the  albumen  farthest  from  the 
hilum. 

Flowers  perfect.     Sepals  herbaceous.    Petals  colored.  CojimelynacEjE. 

Flowers  perfect,  capitate.     Sepals  and  bracts  glumaceous.  Xyridaceje. 

Flowers  monoecious  or  dioecious,  capitate.  Eriocaulonace^e. 

Group  11.  Flowers  imbricated  with  glumaceous  bracts  (glumes),  and  disposed 
in  spikelets  ;  the  proper  perianth  none  or  rudimentary.  Ovary  one-celled, 
one-ovuled.  Seeds  anatropous.  Embryo  at  the  extremity  of  the  albumen 
next  the  hilum. 

Sheaths  of  the  leaves  closed.     Glume  or  bract  single.  Cyperace.£:. 

Sheaths  open.     Glumes  mostly  in  pairs.  Gramine^e. 


484 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


928.  Ol'd.  Palms  (Palms).  Chiefly  trees,  with  unbranched  cylin- 
drical trunks  growing  by  a  terminal  bud.  Leaves  large,  clustered, 
fan-shaped  or  pinnated,  plaited  in  vernation.  Flowers  small,  per- 
fect or  polygamous,  mostly  with  a  double  (6-merous)  perianth  ;  the 
stamens  usually  as  many  as  the  petals  and  sepals  together.  Ovary 
1  _  3-celled,  with  a  single  ovule  in  each  cell.  Fruit  a  drupe  or  berry. 
Seeds  with  a  cartilaginous  albumen,  often  hollow  ;  the  embryo  placed 
in  a  small  separate  cavity.  —  Ex.  Palms,  the  most  majestic  race  of 
plants  within  the  tropics,  and  of  the  highest  value  to  mankind,  are 
scarcely  found  beyond  the  limits  of  these  favored  regions.  The 
Date-tree  (Phoenix  dactylifera,  the  leaves  of  which  are  the  Palms 
of  Scripture),  a  native  of  Northern  Africa,  endures  the  climate  of 
the  opposite  shores  of  the  Mediterranean :  while  in  the  New  World, 
Chamrerops  Palmetto  (Fig.  184),  the  only  arborescent  species  of  the 
United  States,  and  one  or  two  low  Palms  with  a  creeping  caudex 
(Dwarf  Palmetto),  extend  from  Florida  to  North  Carolina.  Palms 
afford  food  and  raiment,  wine,  oil,  wax,  flour,  sugar,  salt,  thread, 
weapons,  utensils,  and  habitations.  The  Cocoanut  (Cocos  nucifera) 
is  perhaps  the  most  important,  as  well  as  the  most  widely  diffused 
species.     Besides  its  well-known  fruit,  and  the  beverage  it  contains, 


the  hard  trunks  are  employed  in  the  construction  of  huts ;  the  ter- 
minal bud  (as  in  our  Palmetto  and  other  Cabbage  Palms)  is  a  deli- 
cious article  of  food ;  the  leaves  are  used  for  thatching,  for  making 

FIG.  1195.  Branch  of  the  inflorescence  of  Chamacrops  hystrix  (Blue  Palmetto).  1197.  A 
sterile  flower.  1198.  Perfect  flower,  with  the  calyx  and  corolla  removed.  1199.  Same,  with 
three  of  the  stamens  removed,  so  as  more  distinctly  to  show  the  three  somewhat  united  carpels. 
1200.  One  of  the  carpels  enlarged,  seen  laterally.  1201.  Same,  with  a  section  of  its  inner  face, 
showing  the  ovule  or  young  seed.  1202.  Vertical  section  of  a  young  cocoanut,  showing  the 
hollow  albumen  ;  and  also  the  small  embryo  in  a  separate  little  cavity.  1203  Section  of  a 
Palm-stem. 


ENDOGENOUS  OR  MONOCOTYLEDONOUS  PLANTS-     485 

hats,  baskets,  mats,  fences,  for  torches,  and  for  writing  upon  ;  the 
stalk  and  midrib  for  oars  ;  their  ashes  yield  abundance  of  potash  ; 
the  juice  of  the  flowers  and  stems  (replete  with  sugar,  which  is 
sometimes  separated  under  the  name  of  Jagery)  is  fermented  into  a 
kind  of  wine,  or  distilled  into  Arrack ;  from  its  spathes  (as  from 
some  other  Palms),  when  wounded,  flows  a  grateful  laxative  bever- 
age, known  in  India  by  the  name  of  Toddy  ;  the  rind  of  the  fruit  is 
used  for  culinary  vessels  ;  its  tough,  fibrous,  outer  portion  is  made 
into  very  strong  cordage  {Coir  rope)  ;  and  an  excellent  fixed  oil  is 
copiously  expressed  from  the  kernel.  Sago  is  procured  from  the 
trunks  of  many  Palms,  but  chiefly  from  species  of  Sagus  of  Eastern 
India.  Canes  and  Rattans  are  the  slender,  often  prostrate,  stems  of 
species  of  Calamus.  —  The  Phytelephas,  or  so-called  Ivory  Palm, 
of  Central  America,  the  seeds  of  which  are  the  Vegetable  Ivory  now 
so  commonly  used  by  the  turner,  in  place  of  ivory,  for  small  articles, 
is  not  a  genuine  Palm,  having  polygamo-dioecious  flowers  with  a 
rudimentary  perianth,  or  none  at  all,  &c.  It  is  proposed  as  the  type 
of  an  order  (Phytelepiianteje)  ;  but  may  for  the  present  be  ap- 
pended to  the  Palms  ;  between  Avhich  and  the  succeeding  orders 
stands  the 

929.  Ord.  PaildanaceSB  ;  tropical  arborescent  plants,  of  Palm-like 
port,  but  their  simplified  diclinous  flowers  destitute  of  a  perianth,  the 
one-celled  ovary  many-ovuled.  The  seeds  of  Pandanus  (the  Screw- 
Pine,  Fig.  140),  &c.  are  eatable.  From  the  young  leaves  of  Car- 
ludovica  the  famous  Panama  hats  are  braided. 

930.  Ol'd.  TypliaceOE  {the  Cat-tail  Family)  consists  of  two  genera ; 
namely,  Typha  (the  Cat-tail),  and  Sparganium  (Bur-reed),  of  no 
important  use.  They  are  spadiceous  plants  with  excessively  re- 
duced flowers,  having  no  perianth. 

931.  Ol'd.  Araceae  {Arum  Family).  Herbs,  with  a  fleshy  corm  or 
rhizoma,  often  shrubby  or  climbing  plants  in  the  tropics ;  the  leaves 
sometimes  compound  or  divided,  commonly  netted-veined.  Flowers 
mostly  on  a  spadix  (often  naked  at  the  extremity),  usually  surround- 
ed by  a  spathe  or  hood  (Fig.  313,  314).  Flowers  commonly  monoe- 
cious, and  destitute  of  envelopes,  or  with  a  single  perianth.  Ovary 
one-  to  several-celled,  with  one  or  more  ovules.  Fruit  a  berry. 
Seeds  with  or  without  albumen.  —  Ex.  Arum,  Calla,  Symplocarpus 
(Skunk-Cabbage),  Orontium,  Acorus  (Sweet  Flag)  :  the  three  latter 
bear  flowers  furnished  with  a  perianth.  —  All  are  endowed  with  an 
acrid  volatile  principle,  which  is  merely  pungent  and  aromatic  in 

41* 


48  G 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


Sweet  Flag  (Acorus  Calamus),  but  extremely  sharp  in  Arum, 
Indian  Turnip,  &c.  The  acrid  principle  of  these  plants  is  volatile, 
and  is  dissipated  by  heat  or  in  drying.  "When  cooked,  their  farina- 
ceous conns  are  eatable.  That  of  Taro  of  the  South  Sea  Islands, 
and  some  other  species  of  Colocasia,  are  important  articles  of  food. 
Symplocarpus  fcetida  exhales  a  strong  odor,  very  like   that  of  the 


skunk,  whence,  as  it  has  large  and  roundish  leaves  in  a  radical  clus- 
ter, it  is  called  Skunk  Cabbage.  The  roots  have  been  used  in  medi- 
cine as  an  antispasmodic. 

932.  Ord.  LeiMaceEB  (Duckweed  Family),  consisting  chiefly  of 
Lemna  (Duckweed  or  Water  Flax-seed)  ;  floating  plants,  with  their 
roots  (if  any)  arising  from  the  bottom  of  a  flat  frond,  and  hanging 
loose  in  the  water ;  their  flowers  produced  from  the  margin  of  the 
frond,  bursting  through  a  membranous  spathe ;  the  sterile,  of  one  or 


FIG.  1204.  Young  leaf,  and  1205,  spathes  and  flowers,  of  Symplocarpus  foetida.  1206.  A 
separate  flower  when  young.  1207.  A  detached  sepal  and  stamen  seen  from  within.  120S.  An 
anther  seen  from  the  front.  1209.  The  spadix  or  collective  head  in  fruit ;  a  quarter-section 
removed,  showing  sections  of  the  immersed  seeds.  1210.  A  seed  detached,  of  the  natural  size. 
1211.  Section  of  the  seed,  with  its  large  globular  embryo  and  plumule  :  in  this  plant  there  i3 
no  albumen. 


ENDOGENOUS    OR    MONOCOTYLEDONOUS    PLANTS. 


487 


two  stamens  ;  the  fertile,  of  a  one-celled  ovary ;  in  fruit  a  utricle  : 
they  are  a  kind  of  minute  and  greatly  reduced  AraceaB,  connecting 
that  order  with  the  next. 


933.  Ord.  MadaceSB  (Pondiceed  Family).  "Water-plants,  with 
cellular  leaves,  and  sheathing  stipules  or  bases :  the  flowers  incon- 
spicuous, sometimes  perfect.  Perianth  simple  and  scale-like,  or 
none.  Stamens  definite.  Ovaries  solitary,  or  two  to  four  and  dis- 
tinct, one-seeded.  Albumen  none.  Embryo  straight  or  curved. — 
Ex.  Potamogeton  (Pondweed),  Najas,  Ruppia,  Zostera  ;  the  two 
latter  in  salt  or  brackish  water. 

934.  Ord.  AlismaceCB  {Water-Plantain  Family).  Marsh  herbs, 
with  the  leaves  and  scapes  usually  arising  from  a  creeping  rhizoma ; 
the  former  either  linear,  or  bearing  a  flat  limb,  which  is  ribbed  or 
nerved,  but  the  veinlets  commonly  reticulated.  Flowers  regular, 
perfect  or  polygamous,  mostly  in  racemes  or  panicles,  not  on  a  spa- 
dix.  Perianth  double,  the  three  petals  commonly  different  from  the 
sepals,  so  as  evidently  to  represent  a  calyx  and  a  corolla.  Seeds  soli- 
tary in  each  carpel  or  cell,  straight  or  curved,  destitute  of  albumen. 
—  Ex.  Alisma  (Water-Plantain),  Sagittaria  (Arrowhead);  belong- 
ing to  the  proper  Alisma  Family,  which  has  the  seed  (and  conse- 


FIO.  1212.  Whole  plant  of  Lemna  minor,  magnified,  bearing  a  staminate  monandrous  flow- 
er. 1213.  An  individual  with  a  diandrous  perfect  flower  ;  which  at  1214  is  seen  separate,  with 
its  spathe,  highly  magnified.  1215.  Flower  of  Lemna  gibba,  much  magnified.  1216.  Vertical 
highly  magnified  section  of  the  pistil  and  the  contained  ovule  of  Lemna  minor.  1217.  The 
fruit,  and  1218,  its  section,  showing  the  seed.  1219.  Section  through  the  highly  magnified 
seed  and  large  embryo. 


488 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


quently  the  embryo)  curved  or  doubled  upon  itself.  Triglochin  and 
Scheuchzeria  chiefly  constitute  the  suborder  Juncagineje  ;  where 
the  seed  and  embryo  are  straight,  and  the  petals  (if  present)  are 
greenish  like  the  calyx.  Slightly  acrid  plants,  and  some  of  them 
astringent. 


935.  Ord.  BlltomacefE,  represented  by  Butomus,  the  Flowering- 
Rush  of  Europe,  and  three  small  tropical  genera,  is  a  form  of  the 
last  with  many  ovules  attached  to  the  whole  face  of  the  carpels : 
these  are  separate  or  combined.     Some  have  a  milky  juice. 

936.  Ord.  Hydrocliaridaceffi  (Frog's-bit  Family)  consists  of  a  few 
aquatic  herbs,  with  dioecious  or  polygamous  regular  flowers  on  scape- 
like peduncles  from  a  spathe,  and  simple  or  double  floral  envelopes, 
which  in  the  fertile  flowers  are  united  in  a  tube,  and  adnate  to  the 
1  —  6-celled  ovary,  more  commonly  one-celled  with  three  parietal 
placentas.  Seeds  numerous,  without  albumen.  —  Ex.  Limnobium, 
Vallisneria,  Anacharis. 

937.  Ol'd.  Orcllidaceae  (Orchis  Family).  Herbs,  of  varied  aspect 
and  form ;  distinguished  from  the  other  orders  with  an  adnate  ovary, 
and  from  all  other  plants,  by  their  irregular  flowers,  with  a  perianth 

FIG.  1220.  Raceme  or  spike  of  Triglochin  palustre.  1221.  Enlarged  flower.  1222.  A  petal 
and  stamen.  1223.  The  club-shaped  capsule.  1224.  A  magnified  seed,  exhibiting  the  rhaphe 
and  chalaza.  1225.  Embryo  of  the  same.  1226.  Vertical  section  of  the  same,  bringing  the 
plumule  to  view.  1227.  Cross-section  (more  magnified),  showing  the  cotyledon  wrapped 
around  the  plumule. 

FIG.  1228.  Leaf,  and  1229,  flower,  of  Alisma  Plantago.  1230.  More  enlarged  flower,  with 
the  petals  removed.  1231.  Carpel,  with  the  ovary  divided,  showing  the  doubled  ovule.  1232. 
Vertical  section  of  the  germinating  seed  of  Alisma  Damasonium ;  a,  the  cotyledon  ;  6,  the  plu- 
mule ;  c,  the  protruding  radicle. 


ENDOGENOUS    OR    MONOCOTYLEDONOUS    TLANTS. 


489 


of  six  parts  ;  their  single  fertile  stamen  (or  in  Cypripeclium  their 
two  stamens)  coherent  with  the  style  (composing  the  column)  ;  their 
pollen  usually  combined  into  two  or  more  granular  or  waxy  masses 
(pollinia)  ;    the    ovary   one-celled,    with   three   parietal  placentae, 


covered  with  numerous  minute  seeds.  — Ex.  Orchis,  Cypripedium 
(Ladies'  Slipper),  Arethusa,  &c.  In  the  tropics  many  are  Epiphytes 
(149,  Fig.  144).  Many  are  cultivated  for  their  beauty  and  singu- 
larity. The  tuberiferous  roots  are  often  filled  with  a  very  dense 
mucilaginous  or  glutinous  substance  (as  those  of  our  Aplectrum, 
thence  called  Putty-root).  Of  this  nature  is  the  Salep  of  commerce, 
the  produce  of  some  unascertained  species  of  Middle  Asia.  The 
fragrant  Vanilla  is  the  fleshy  fruit  of  Vanilla  planifoha  and  other 
tropical  American  species.  The  roots  of  Cypripedium  are  used  as 
a  substitute  for  Valerian. 

938.  Oril.  ZingibCMCete  {Ginger  Family)  consists  of  some  mostly 
showy  tropical  aromatic  herbs,  the  nerves  of  their  leaves  diverging 


FIG.  1233.  Orchis  spectabilis  :  a,  a  separate  flower.  1234.  Column  (somewhat  magnified), 
from  which  the  other  parts  are  cut  away  :  the  two  anther-cells  opening  and  showing  the  pollen- 
masses.  1235.  Magnified  pollen-mass,  with  its  stalk.  1236.  Arethusa  bulbosa.  1237.  The 
column,  enlarged :  the  anther  terminal  and  opening  by  a  lid.  1238.  Magnified  anther,  with 
the  lid  removed,  showing  the  two  pollen-masses  in  each  cell. 


490  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

from  a  midrib ;  the  adnate  perianth  irregular  and  triple  (having  a 
corolla  of  two  series  as  well  as  a  calyx)  ;  fertile  stamen  one,  on  the 
anterior  side  of  the  flower,  free  ;  the  fruit  a  three-celled  capsule  or 
berry ;  the  seeds  several :  with  the  embryo  in  a  little  sac  at  one 
extremity  of  the  farinaceous  albumen.  —  There  are,  in  fact,  six 
stamens  in  the  androecium,  the  three  exterior  petaloid  and  forming 
the  so-called  inner  corolla,  and  two  of  the  inner  verticel  are  sterile. 
—  Their  properties  and  economical  uses  are  well  represented  by  the 
pungent  aromatic  rootstock  of  Ginger  (Zingiber  officinale),  Galin- 
gale  (Alpinia  Galanga,  &c),  the  seeds  of  Cardamon,  &c.  The  same 
cordial  qualities  in  lesser  degree  exist  in  the  roots  of  Curcuma 
longa,  &c.  which  furnish  the  coloring  matter  called  Turmeric  ;  while 
other  species  yield  starch,  like  the  closely  allied 

939.  Ol'd.  CannaceOB  {Arrowroot  Family),  which  also  consists  of  trop- 
ical plants,  differs  from  the  preceding  chiefly  in  the  want  of  aroma, 
and  in  having  the  single  fertile  stamen  posterior,  with  a  one-celled 
anther.  —  Ex.  Maranta  arundinacea,  Avhich  yields  the  Arrowroot  of 
the  "West  Indies  ;  the  tubers  of  which  are  filled  with  starch. 

940.  Ol'd.  MusaceSB  {Banana  Family).  Tropical  plants,  of  which 
the  Banana  and  Plantain  are  the  type ;  distinguished  by  their 
simple  perianth  and  five  or  six  perfect  stamens.  The  fruit  is  an 
important  staple  of  food  in  the  tropics  ;  the  gigantic  leaves  are  used 
in  thatching ;  and  the  fibres  of  Musa  textilis  yield  Manilla  hemp,  as 
well  as  a  finer  fibre  from  which  some  of  the  most  delicate  India  mus- 
lins are  made. 

941.  Ol'd.  Burinaillliacese  consists  of  small,  mostly  tropical,  annual 
herbs,  commonly  with  a  one-celled  ovary  and  three  parietal  placentas, 
(but  in  several  the  ovary  is  three-celled)  ;  differing  from  Orchidaceae 
by  their  regular  flowers  with  three  stamens  ;  and  from  Iridaceaa  by 
the  position  of  these  before  the  inner  divisions  of  the  perianth,  the 
introrse  anthers,  &c.  —  Ex.  Burmannia  and  Apteria,  of  the  South- 
ern States. 

942.  Ord.  Il'idaceSB  {Iris  Family).  Perennial  herbs ;  the  flower- 
stems  springing  from  bulbs,  corms,  or  rhizomas,  rarely  with  fibrous 
roots,  mostly  with  equitant  leaves.  Flowers  regular  or  irregular, 
showy,  often  springing  from  a  spathe.  Perianth  with  the  tube  ad- 
herent to  the  three-celled  ovary,  and  usually  elongated  above  it ;  the 
limb  six-parted,  in  two  series.  Stamens  three,  distinct  or  monadel- 
phous  ;  the  anthers  extrorse  !  Stigmas  three,  dilated  or  petaloid  ! 
Seeds  with   hard   albumen.  —  Ex.   Iris,  Crocus.     The   rootstocks, 


ENDOGENOUS    OR   MONOCOTYLEDONOUS    PLANTS. 


491 


corms,  &c.  contain  starch,  with  some  volatile  acrid  matter.     Those 
of  Iris  cristata  are  very  pungent ;  those  of  I.  versicolor,  &c.  are 


drastic.  Orris-root  is  the  dried  rhizoma  of  Iris  florentina,  of  South- 
ern Europe.  The  true  Saffron  consists  of  the  dried  orange-colored 
stigmas  of  Crocus  sativus. 

943.  Ord.  AraaryllidacCEB  (Amaryllis  Family).  Bulbous  plants 
(sometimes  with  fibrous  roots),  bearing  showy  flowers  mostly  on 
scapes.  Perianth  regular,  or  nearly  so ;  the  tube  adherent  to  the 
ovary,  and  often  produced  above  it,  six-parted.  Stamens  six,  dis- 
tinct, with  introrse  anthers.  Stigma  undivided  or  three-lobed. 
Fruit  a  three-celled  capsule  or  berry.  Seeds  with  fleshy  albumen. 
— Ex.  Amaryllis,  Narcissus,  Crinum,  &c. ;  mostly  ornamental  plants. 
The  bulbs  acrid,  emetic,  &c. :  those  of  Hamaanthus  (with  whose  juice 
the  Hottentots  poison  their  arrows)  are  extremely  venomous.  The 
fermented  juice  of  Agave  is  the  intoxicating  Pulque  of  the  Mexicans. 
Hypoxys,  which  has  been  taken  as  the  type  of  an  order,  may  prop- 
erly be  referred  to  this  family. 

FIO.  1239.  Iris  cristata.  1240.  The  summit  of  the  style,  petaloid  stigmas,  and  stamens. 
1241.  Vertical  section  of  the  ovary  (the  equitant  leaves  cut  away)  and  long  tube  of  the  peri- 
anth. 1242.  Cross-section  of  the  pod.  1243.  Seed.  1244.  Enlarged  section  of  the  same,  show- 
ing the  embryo,  &c. 


492  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

944.  Ol'd.  BromeliaceEB  {Pine-Apple  Family)  consists  of  American 
and  chiefly  tropical  plants ;  with  rigid  and  dry  channelled  leaves, 
often  with  a  scurfy  surface,  a  mostly  adnate  perianth  of  three  sepals 
and  three  petals,  and  six  or  more  stamens  ;  the  seeds  with  mealy 
albumen.  —  Ex.  Ananassa,  the  Pine- Apple  ;  the  fine  fruit  of  which 
is  formed  by  the  consolidation  of  the  imperfect  flowers,  bracts,  and 
receptacle  into  a  succulent  mass.  Tillandsia,  the  Black  Moss  or 
Long  Moss  (which,  like  most  Bromelias,  grows  on  the  trunks  and 
branches  of  trees  in  the  warmer  and  humid  parts  of  America),  has 
the  ovary  free  from  the  perianth. 

945.  Ol'd.  IIiClllOlloraceBB  {Bloodioort  Family)  is  composed  of  peren- 
nial herbs,  with  fibrous  roots,  equitant  or  ensiform  leaves  ;  which, 
with  the  stems  and  flowers,  are  commonly  densely  clothed  with 
woolly  hairs  or  scurf.  Perianth  with  the  tube  either  nearly  free 
from,  or  commonly  adherent  to,  the  three-celled  ovary;  the  limb 
six-cleft,  regular.  Stamens  six,  or  only  three,  with  introrse  anthers. 
Style  single,  the  stigma  standing  over  the  dissepiments  of  the  ovary. 
Embryo  in  cartilaginous  albumen.  —  Ex.  Lachnanthes  (Red-Eoot), 
Lophiola.  —  Some  have  a  red  juice.  The  roots  are  astringent  and 
tonic,  especially  in  Aletris. 

946.  Ol'd.  DiosCOl'eaceoe  ( Tarn  Family)  consists  of  a  few  twining 
plants,  with  large  tuberous  roots  or  knotted  rootstocks  ;  distinguished 
among  Endogens  by  their  ribbed  and  netted-veined  leaves,  with  dis- 
tinct petioles,  and  by  their  inconspicuous  dioecious  flowers,  with  the 
perianth  in  the  pistillate  flowers  adherent  to  the  ovary;  the  limb 
six-cleft  in  two  series.  Stamens  six.  Ovary  three-celled,  with  only 
one  or  two  ovules  in  each  cell :  styles  nearly  distinct.  Fruit  often 
a  three-winged  capsule.  Albumen  cartilaginous.  —  Ex.  Dioscorea. 
The  tubers  of  one  or  or  more  species,  filled  with  starch  and  mucilage 
(but  more  or  less  acrid  until  cooked),  are  Yams,  an  important  article 
of  food  in  tropical  countries. 

947.  Ol'd.  SmilacefB  (Smilax  Family)  is  also  remarkable  among 
Endogens  for  netted-veined  leaves.  It  consists  both  of  herbs  and  of 
shrubby  plants  climbing  by  tendrils  ;  the  perianth  is  free  from  the 
ovary ;  the  mostly  three  styles  or  sessile  stigmas  are  entirely  dis- 
tinct ;  the  anthers  are  introrse  ;  and  the  fruit  is  a  berry.  Embryo 
minute,  in  hard  albumen.  —  In  the  True  Smilax  Family,  the  flowers 
are  dioecious  and  axillary;  the  six  divisions  of  the  perianth  are 
alike ;  the  anthers  are  one-celled,  and  the  few  seeds  are  orthotropous 
and   pendulous.     They   are   mostly   shrubby   and   alternate-leaved 


ENDOGENOUS  OR  MONOCOTYLEDONOUS  PLANTS. 


493 


plants.  Ex.  Smilax  (Greenbrier,  &c.) ;  far  the  most  important 
species  is  S.  officinalis  of  tropical  America,  the  rootstocks  of  which 
are  the  officinal  Sarsaparilla. 

948.  Subord.  Trilliaceee  {Trillium  Family)  consists  of  low 
herbs,  with  whorled  leaves  and  per- 
fect flowers,  which  in  the  largest 
genus,  Trillium,  have  a  green  calyx 
and  a  colored  corolla;  the  anthers 
are  two-celled  ;  the  seeds  anatropous 
and  rather  numerous.  —  The  short 
rootstock  of  Trillium  (Fig.  169), 
called  Birthroot,  has  a  place  in  the 
popular  materia  medica  ;  but  it  is 
doubtful  if  it  really  possesses  any 
useful  properties. 

949.  Ol*d.  LiliaCGCE  {Lily  Family).  Herbs, 
with  the  flower-stems  springing  from  bulbs, 
tubers,  or  with  fibrous  or  fascicled  roots. 
Leaves  simple,  sheathing  or  clasping  at  the 
base,  parallel-veined.  Flowers  regular,  per- 
fect. Perianth  colored,  mostly  of  six  parts, 
or  six-cleft.     Stamens  six:  anthers  introrse.  1216 

Ovary  free,  three-celled :  the  styles  united  into  one.  Fruit  capsular 
or  baccate,  with  several  or  numerous  seeds  in  each  cell.  Albumen 
fleshy.  —  This  large  and  widely  diffused  order  comprises  a  great 
variety  of  forms  :  the  Lily,  Dog-tooth  Violet,  and  Tulip  represent  one 
division ;  the  Tuberose,  a  second ;  the  Aloe  and  Yucca,  a  third ; 
the  Hyacinth,  the  Onion,  Leek,  and  Garlic  (Allium),  and  the  As- 
phodel, a  fourth ;  the  Asparagus,  Lily  of  the  Valley,  and  Solomon's 
Seal,  a  fifth,  which  is  nearly  allied  to  the  order  Smilacerc.  Acrid 
and  often  bitter  principles  prevail  in  the  order,  and  are  most  concen- 
trated in  the  bulbs,  &c,  which  abound  in  starchy  or  mucilaginous 
matter,  and  are  often  edible  when  cooked.  Squills  are  the  bulbs  of 
Scilla  maritima  of  the  South  of  Europe.  Aloes  is  the  acrid  and 
bitter  inspissated  juice  of  the  succulent  leaves  of  species  of  Aloe. 
The  original  Dragon's-blood  Avas  derived  from  the  juice  of  the  fa- 
mous Dragon-tree  (Dracama  Draco)  of  the  East.  —  The  leaves 
of   Phormium  tenax   yield  the   New    Zealand  hemp,   one   of  the 


FIG.  1245.     A  flower  of  Trillium  erectum  ;  a  front  view.     1246.  A  diagram  of  the  same. 

42 


494 


ILLUSTRATIONS    OF   THE    NATURAL    ORDERS. 


strongest  vegetable  fibres  known.     Many  are  the  ornaments  of  our 
gardens  and  conservatories. 


950.  Ord,  MelanthaceSB  {Colchicum  Family).  Herbs,  with  bulbs, 
corms,  or  fasciculated  roots.  Perianth  regular,  in  a  double  series ; 
the  sepals  and  petals  either  distinct,  or  united  below  into  a  tube. 
Stamens  six,  with  extrorse  anthers  (except  in  Tofieldia  and  Pleea). 
Ovary  free,  three-celled,  several-seeded :  styles  distinct.  Albumen 
fleshy.     The  true  Melanthaceae,  or 

951.  Suboi'd.  MelfintllieBB  have  a  mostly  septicidal  capsule  and  a 
marcescent  or  persistent  perianth.  —  Ex.  Colchicum  has  a  perianth 
with  a  long  tube,  arising  from  a  subterranean  ovary ;  it  is  also  re- 
markable for  flowering  in  the  autumn,  when  it  is  leafless,  ripening 
its  fruit  and  producing  its  leaves  the  following  spring.  In  most  of 
the  order,  the  leaves  of  the  perianth  are  uncombined ;  as  in  Vera- 
trum  ("White  Hellebore),  Helonias,  &c.  Acrid  and  drastic  poison- 
ous plants,  with  more  or  less  narcotic  qualities  ;  chiefly  due  to  a 
peculiar  alkaloid   principle,  named  Veratria,  which  is  largely  ex- 


FIG.  1247.  Erythronium  Americanum  (Dog-tooth  Violet,  Adder's-tongue).  1248.  The 
bulb.  1249.  Perianth  laid  opeiij  with  the  stamens.  1250.  The  Pistil.  1251.  Cross-section 
of  the  capsule. 


ENDOGENOUS  OR  MONOCOTYLEDONOUS  PLANTS. 


495 


tracted  from  the  seeds  of  Sabadilla,  or  Cebadilla;  the  produce  of 
Schcenocaulon  officinale,  &c.  of  the  Mexican  Andes.  The  seeds  and 
the  corms  of  Colchicum  are  used  in  medicine. 


952.  Subord.  UvularieS  (Bellwort  Family)  has  a  few-seeded  loculi- 
cidal  capsule  or  berry,  more  or  less  united  styles,  and  a  deciduous 
perianth  ;  the  stems  from  rootstocks.  —  Ex.  Uvularia. 

953.  Ord.  JuncaceSD  {Rush  Family).  Herbaceous,  mostly  grass- 
like plants,  often  leafless ;  the  small  glumaceous  flowers  in  clusters, 
cymes,  or  heads.  Perianth  mostly  dry,  greenish  or  brownish,  of  six 
leaves  (sepals  and  petals)  in  two  series.  Stamens  six,  or  three : 
anthers  introrse.  Ovary  free,  three-celled,  or  one-celled  from  the 
placenta?  not  reaching  the  axis  ;  their  styles  united  into  one :  stig- 
mas three.  Capsule  three-valved,  few-  or  many-seeded.  Albumen 
fleshy.  —  Ex.  Juncus  (Rush). 

954.  Ord.  FoiltederiaCCSB  (Pickerel-weed  Family)  comprises  a  few 
aquatic  plants,  with  the  flowers,  either  solitary  or  spicate,  arising 
from  a  spathe  or  from  a  fissure  of  the  petiole ;  the  six-cleft  and 
colored  perianth  persistent  and  withei'ing,  often  adherent  to  the  base 
of  the  three-celled  ovary ;  the  stamens  three,  and  inserted  on  the 


FIG.  1252.  Colchicum  autumnale  ;  a  flowering  plant.  1253.  Perianth  laid  open.  1254. 
Pistil,  with  the  long  distinct  styles.  1255.  Leafy  stem  and  fruit  (capsule  opening  by  septi- 
cidal  dehiscence).  1256.  Capsule  divided  transversely.  1257.  Section  of  a  seed,  and  a  sep- 
arate embryo. 


496        ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 

throat  of  the  perianth,  or  six,  and  unequal  in  situation.  Ovules 
anatropous,  numerous  ;  hut  the  fruit  often  one-celled  and  one-seeded. 
—  Ex.  Pontederia  (Pickerel-weed),  Heteranthera,  &c. 

955.  Ord.  ComilielynaceiC  {Spiderwort  Family),  with  usually  sheath- 
ing leaves ;  distinguished  from  other  Endogens  (except  Alismaceoe 
and  Trillium)  by  the  manifest  distinction  between  the  calyx  and 
corolla ;  the  former  of  three  herbaceous  sepals ;  the  latter  of  as 
many  delicate  colored  petals.  Stamens  six,  or  fewer :  anthers  with 
two  separated  cells :  filaments  often  clothed  with  jointed  hairs, 
hypogynous.  Ovary  two-  or  three-celled :  styles  united  into  one. 
Capsule  few-seeded,  loculicidal.  Seeds  orthotropous.  Embryo 
small,  pulley-shaped,  partly  sunk  in  the  apex  of  the  albumen. — 
Ex.  Commelyna,  Tradescantia  (Spiderwort)      Mucilaginous  plants. 

956.  Ol'd.  Xjl'idaceSB.  Low,  rush-like  plants  ;  with  ensiform,  grassy 
or  filiform  radical  leaves,  sheathing  the  base  of  a  simple  scape, 
which  bears  a  head  of  flowers  at  the  apex,  imbricated  with  bracts. 
Calyx  of  three  glumaceous  sepals,  caducous.  Petals  three,  with 
claws,  more  or  less  united  into  a  monopctalous  tube.  Stamens  six, 
inserted  on  the  corolla ;  three  of  them  bearing  extrorse  anthers, 
the  others  mere  sterile  filaments.  Ovary  one-celled,  with  three 
parietal  placentae,  or  three-celled :  styles  partly  united :  stigmas 
lobed.  Capsule  many-seeded.  Seeds  orthotropous,  albuminous.  — 
Ex.  Xyris  (Yellow-eyed  Grass). 

957.  Ord.  EriocaillonacetB  {Pipewort  Family).  Aquatic  or  marsh 
herbs,  with  much  the  structure  of  the  preceding ;  their  leaves  cel- 
lular or  fleshy  ;  their  minute  flowers  (monoecious  or  dioecious) 
crowded,  along  with  scales  or  hairs,  into  a  very  compact  head  :  the 
corolla  less  petaloid  than  in  Xyridacea? ;  the  six  stamens  often  all 
perfect ;  the  ovules  and  seeds  solitary  in  each  cell.  — Ex.  Eriocaulon. 

958.  Ord.  Restiaceae  consists  of  South  African  and  Australian 
Rush-like  plants,  with  the  aspect  of  Cyperaceae,  but  with  one-celled 
anthers  and  orthoti'opous  seeds. 

959.  Ol'd.  CyperaeeSB  {Sedge  Family).  Stems  {culms)  usually 
solid,  casspitose.  Sheaths  of  the  leaves  closed.  Flowers  one  in  the 
axil  of  each  glumaceous  bract.  Perianth  none,  or  a  few  bristles. 
Stamens  mostly  three,  hypogynous.  Styles  two  or  three,  more  or 
less  united.  Fruit  an  achenium.  Embryo  small,  at  the  extremity 
of  the  seed  next  the  hilum.  —  Ex.  Cyperus,  Scirpus,  Carex  (Sedges). 
The  herbage  is  little  eaten  by  cattle.  Some  Clubrushes  are  used 
for  making  mats,  chair-bottoms,  &c.     The  papyrus  of  the  Egyptians 


ENDOGENOUS  OR  MONOCOTYLEDONOUS  PLANTS. 


497 


was  made  from  the  stems  of  Cyperus  Papyrus.  The  tubers  of 
C.  esculentus  are  sweet  and  edible,  but  are  too  small  to  be  of  much 
value  for  food. 

1262 


960.  Ol'd.  GramilieSB  ( Grass  Family).  Stems  (culms)  cylindrical, 
mostly  hollow,  and  closed  at  the  nodes.  Sheaths  of  the  leaves  split 
or  open.  Flowers  in  little  spikelets,  consisting  of  two-ranked  imbri- 
cated bracts  ;  of  which  the  exterior  are  called  glumes,  and  the  two 
that  immediately  enclose  each  flWer,  palece.  Perianth  none,  or  in 
the  form  of  very  small  and  membranous  hypogynous  scales,  from 
one  to  three  in  number,  distinct  or  united  (termed  squamulce,  squa- 
mellce,  or  lodiculce).  Stamens  commonly  three :  anthers  versatile. 
Styles  or  stigmas  two ;  the  latter  feathery.  Fruit  a  caryopsis. 
Embryo  situated  on  the  outside  of  the  farinaceous  albumen,  next  the 


FIG.  1258.  Scirpus  triqueter,  -with  its  cluster  of  spikelets.  1259.  A  separate  flower,  en- 
larged, showing  its  rudimentary  perianth  of  a  few  denticulate  bristles,  its  three  stamens,  and 
pistil  with  a  three-cleft  style :  a,  section  of  the  seed,  showing  the  minute  embryo.  1260.  Ca- 
rex  Careyana,  reduced  in  size  (flowers  monoecious,  the  two  kinds  in  different  spikes).  1261. 
Stem,  with  the  staminate  and  upper  pistillate  spike,  of  the  size  of  nature.  1262.  A  scale  of 
the  staminate  spike,  with  the  flower  (consisting  merely  of  three  stamens)  in  its  axil.  1263. 
Magnified  pistillate  flower,  with  its  scale  or  bract :  the  ovary  enclosed  in  a  kind  of  sac  (perigy- 
nium),  formed  by  the  union  of  two  bractlets.  1264.  Cross-section  of  the  perigynium;  with 
the  pistil,  p,  removed.    1265.     Vertical  section  of  the  achenium,  showing  the  seed. 

42* 


498 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


hilum  (Fig.  126-128,  G22  -  C24).  —  J5r.  Agrostis,  Phleum,  Poa, 
Festuca,  which  are  the  principal  meadow  and  pasture  grasses :  Ory- 
za  (Rice),  Zea  (Maize),  Avena  (the  Oat),  Triticum  (Wheat),  Secale 
(Rye),  Hordeum  (Barley),  are  the  chief  cereal  plants,  cultivated  for 
their  farinaceous  seeds.  This  universally  diffused  order  is  one  of 
the  largest  of  the  vegetable  kingdom,  and  doubtless  the  most  impor- 
tant ;  the  floury  albumen  of  the  seeds  and  the  nutritious  herbage 
constituting  the  chief  support  of  man  and  the  herbivorous  animals. 
No  unwholesome  properties  are  known  in  the  family  except  in  the 
grain  of  Darnel,  which  is  deleterious.  Ergot,  or  Spurred  Rye,  is 
no  exception,  being  a  morbid  growth,  caused  by  a  parasitic  fungus. 
The  stems  of  grasses  frequently  contain  sugar  in  considerable  quan- 
tity (especially  when  they  are  solid) ;  as  in  Maize,  the  sweet  variety 
of  Sorghum  vulgare,  or  Broom-Corn,  and  in  Sugar-Cane  (Saccharum 
ofncinarum),  which  affords  the  principal  supply  of  this  article. 


1271  1275 


1278  1277  1278 


FIG.  126G.  One-flowered  spikelet  or  loeusta  of  Alopecurus,  with  the  glumes  separated. 
1267.  Same,  with  the  glumes  removed :  an  awn  on  the  back  of  the  outer  palea.  1268.  One- 
flowered  spikelet  of  an  Agrostis.  1269.  Pistil  of  a  Grass,  showing  the  two  feathery  stigmas, 
and  the  two  hypogynous  scales  or  squamuhe,  larger  than  usual  (representing  the  perianth). 
1270.  Two-flowered  spikelet  of  an  Avena  ;  with  the  glumes  spreading.  1271.  One  of  the  flow- 
ers with  its  paleee  ;  the  exterior  pointed,  with  two  bristles  or  cusps  at  the  apex,  and  with  a 
bent  awn  on  the  back.  1272.  Many-flowered  spikelet  of  Glyeeria  fluitans.  1273.  An  enlarged 
separate  flower  of  the  same,  seen  from  within,  showing  the  inner  palea;,  &c.  1274.  The  fruit 
(caryopsis)  of  the  Wheat,  with  an  oblique  section  through  the  integuments  of  the  embryo, 
which  is  exterior  to  the  albumen.  1275.  Detached  magnified  embryo  :  a,  the  imperfect  cotyle- 
don ;  b,  the  first  leaf  of  the  plumule;  c,  the  second  leaf  of  the  plumule ;  rf,  the  radicle.  1276. 
The  caryopsis  of  Hordeum  (Barley;.  1277.  A  cross-section.  1278.  A  vertical  section,  show- 
ing the  external  embryo  at  the  base.  1279.  Magnified  detached  embryo,  with  its  broad  cotyle- 
don and  the  plumule.  1280.  More  magnified  vertical  section  of  the  same :  a,  the  plumule  ;  b, 
the  radicle. 


CRYPTOGAMOUS    OR    FLOWERLESS    PLANTS. 


499 


Series  II.     Cryptogamous  or  Flowerless  Plants. 

Plants  destitute  of  proper  flowers  (stamens  and  pistils),  and 
propagated  by  spores  instead  of  seeds. 

Class  III.     Acrogenous  Plants.* 


Vegetables  with  a  distinct  axis,  growing  from  the  apex,  with  no 
provision  for  subsequent  increase  in  diameter  (containing  woody  and 
vascular  tissue),  and  usually  with  distinct  foliage. 

9G1.  Ol'd.  EquisetacefC  {Horsetail  Family).  Leafless  plants ;  with 
striated,     jointed,      simple      or  ]282  1231 

branched  stems  (containing  ducts 
and  some  spiral  vessels),  which 
are  hollow  and  closed  at  the 
joints  ;  each  joint  terminating  in 
a  toothed  sheath,  which  surrounds 
the  base  of  the  one  above  it.  In- 
florescence consisting  of  peltate 
scales  crowded  in  a  terminal 
spike,  or  kind  of  strobile  :  each 
with  several  thecce  attached  to  its 
lower  surface,  longitudinally  de- 
hiscent. Spores  numerous,  with 
four  elastic  club-shaped  bodies 
(of  unknown  use),  wrapped 
around  them  when  moist,  or 
spreading  when  dry.  —  Ex.  Equi- 
setum.  The  epidermis  of  Equi- 
setum  hyemale  (the  well-known 
Scouring  Rush)  contains  so  much 
silex  that  it  is  used  for  polishing. 


*  For  illustrations  of  Classes  III.  and  IV.  see  the  plates  of  Manual  of  the 
Botany  of  the  Northern  United  States. 

FIG.  1281.  Summit  of  the  stem  of  Equisetum  sylvaticum.  1282.  Part  of  the  axis  of  the 
fructification,  with  some  of  the  fruit-bearing  organs,  shown  magnified  in  Fig.  1283,  a  view  from 
underneath.  1284.  A  separate  theca,  or  spore-case,  more  magnified.  1285,  12S6.  Spores,  with 
the  club-shaped  appendages  more  magnified. 


500 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


962.  Ord.  Filices  (Ferns).  Leafy  plants  ;  with  the  leaves  (fronds) 
spirally  rolled  up  or  circinate  in  vernation  (except  in  one  suborder), 
usually  rising  from  prostrate  or  subterranean  rootstocks,  or  in  tree- 
Ferns  from  an  erect  arborescent  trunk  (Fig.  100),  and  bearing  on 
the  veins  of  their  lower  surface,  or  along  the  margins,  the  simple 
fructification,  which  consists  of  one-celled  spore-cases  (thecce  or  spo- 
rangia), opening  in  various  ways,  and  discharging  the  numerous 


minute  spores.     The  stalk  or  petiole  of  the  frond  is  termed  a  stipe. 
—  There  are  four  principal  suborders,  viz. :  — 


FIG.  1287.  Camptosorus  rhizophyllus  (Walking  Fern) ;  the  fronds  rooting,  as  they  fre- 
quently do,  at  the  apex ;  the  sori  occupying  the  reticulated  veins  on  the  back.  1238.  Division 
(pinnula)  of  a  frond  of  Aspidium  Goldianum  ;  the  roundish  sori  attached  to  the  simple  veins, 
and  covered  with  an  indusium,  which  is  fastened  in  the  centre,  and  opens  all  around  the  mar- 
gin. 1289.  Magnified  sporangium  of  this  division  of  Ferns,  with  its  stalk,  and  elastic  ring 
partly  surrounding  it ;  which,  tending  to  straighten  itself  when  dry,  tears  open  the  sporangium, 
shedding  the  minute  spores  (1290).  1291.  Sehizsea  pusilla  of  about  the  natural  size,  with  simple 
and  slender  radical  leaves  ;  the  contracted  fertile  frond  pinnate.  1292.  A  division  (pinna)  of 
the  fertile  frond,  magnified,  showing  the  sessile  sporangia  occupying  its  lower  surface.  1293. 
One  of  the  sporangia  more  magnified ;  they  have  no  proper  ring,  and  open  by  a  longitudinal 
cleft.  1294.  Ophioglossum  vulgatum  (Adder's-tongue)  ;  the  sporangia  forming  a  two-ranked 
spike  on  a  transformed  and  contracted  frond :  a,  portion  of  the  spike  enlarged,  showing  the  co- 
riaceous sporangia,  destitute  of  a  ring,  and  opening  transversely. 


CRYPTOGAMOUS    OR    FLOWERLESS    PLANTS. 


501 


963.  Subord,  PolypodinCiT.  Sporangia  collected  in  dots,  lines,  or 
variously  shaped  clusters  (sori  or  fruit-dots)  on  the  hack  or  margins 
of  the  frond  or  its  divisions,  or  rarely  covering  the  whole  surface, 
stalked,  cellulai'-reticulated,  the  stalk  running  into  a  vertical  incom- 
plete ring,  which  hy  straightening  at  maturity  ruptures  the  sporan- 
gium transversely  on  the  inner  side,  discharging  the  spores.  Fruit- 
dots  often  covered,  at  least  when  young,  by  a  membrane  called  the 
involucre,  or  more  properly  the  indusium. 

964.  Subord.  Ilyilieiiophyllea:.  Sporangia  borne  on  a  vein  extended 
beyond  the  margin  of  the  frond  into  a  setiform  receptacle,  sessile,  and 
surrounded  by  a  horizontal  complete  ring  ;  otherwise  as  in  the  last. 
—  Ex.  Hymenophyllum,  Trichomanes.  Ferns  of  very  delicate 
texture,  chiefly  tropical. 

965.  Subord.  OsmillldineEC.     Sporangia  variously  collected,  cellular- 
reticulated,  destitute  of  any  ring   (as   in   Osmunda  or   Flowering 
Fern),  or  with  an  imperfect  trans-  1236 
verse  ring  around  the  top  (as    in 
Schizrca,     Fig.      1293),     opening 
lengthwise  by  a  regular  slit. 

966.  Subord.  Ophioglossesc.  Spo- 
rangia spiked,  closely  sessile,  naked, 
coriaceous  and  opaque,  not  reticu- 
lated, destitute  of  a  ring,  opening 
by  a  transverse  slit  into  two  valves, 
discharging  the  very  copious  spores 
Avhich  appear  like  floury  dust. 
Fronds  straight,  never  rolled  up  (or 
circinate)  in  the  bud  ! 

967.  Ord.  Lycopodiacea;  (Club-3foss 

Family).     Plants  with  creeping  or 

erect  leafy  stems,  mostly  branching ; 

the   crowded   leaves   lanceolate  or 

subulate,    one-nerved.      Sporangia 

single   and  sessile  in   the   axils  of 

the  leaves,  sometimes  all  crowded  m5 

at  the  summit  under  leaves  which  are  changed  into  bracts  and  form 


FIG.  1295.  Lycopodium  Carolinianum,  of  the  natural  size.  1296.  A  leaf  from  the  spike  of 
fructification,  with  the  spore-case  in  its  axil,  and  spores  falling  out.  1297.  A  group  of  four 
larger  spores  (oophoridia)  of  Selaginella,  magnified.  1298.  The  same,  separated.  1299.  A  burst 
spore-case  of  Selaginella  apus,  with  its  four  large  spores. 


502  ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 

a  kind  of  anient,  one-celled,  or  rarely  two-  to  three-celled,  dehiscent, 
containing  either  minute  grains,  appearing  like  line  powder,  or  a  few 
rather  large  sporules  ;  both  kinds  often  found  in  the  same  plant.  — 
Ex.  Lycopodium  (Club-Moss,  Ground  Pine),  Selaginella. — Append- 
ed to  this  family,  rather  than  to  the  next  (with  which  it  has  gener- 
ally been  associated),  is  the 

968.  Suboi'd.  Isoctilieae  (Quillwort  Family),  consisting  of  a  few 
acaulescent  submersed  aquatics,  with  their  sporangia  in  the  axils 
and  immersed  in  the  inflated  base  of  the  grassy  subulate  leaves.  — 
Ex.  Isoetes. 

9G9.  Ol'd.  Ilydl'Opterides.  Aquatic  or  marshy  cryptogamous  plants, 
of  diverse  habit,  with  the  fructification  borne  at  the  bases  of  the 
leaves,  or  on  submerged  branches :  this  consists  of  two  sorts  of  or- 
gans, contained  in  indehiscent  or  irregularly  bursting  involucres 
(sporocarps).     It  comprises  the 

970.  Sllbord.  Mai'SilaceOC  (Pepperwort  Family)  ;  with  creeping  stems ; 
the  leaves  long-stalked,  circulate  in  vernation,  and  of  four  obcordate 
leaflets  in  Marsilea,  or  filiform  and  destitute  of  leaflets  in  Pilularia 
(the  Pillwort). 

971.  Suboi'd.  SalvinieSB ;  which  are  free  floating  plants,  with  alter- 
nate and  sometimes  imbricated  sessile  leaves  ;  the  fructification 
borne  on  the  stem  or  branches  underneath.  —  Ex.  Salvinia,  Azolla. 
(For  illustrations,  see  Manual  of  Botany,  Plate  14.) 

Class  IV.     Anophytes. 

Vegetables  composed  of  parenchyma  alone,  with  acrogenous 
growth,  usually  with  distinct  foliage,  sometimes  the  stem  and  foliage 
confluent  into  a  frond. 

972.  Ol'd.  Musci  {Mosses).  Low,  tufted  plants,  always  with  a  stem 
and  distinct  (sessile)  leaves,  producing  spore-cases  which  mostly 
open  by  a  terminal  lid,  and  contain  innumerable  simple  spores.  The 
fertilizing  organs,  or  antheridia,  have  been  elsewhere  mentioned.  In 
Mosses  these  accompany  the  pistillidia ;  the  latter  develop  into  the 
capsule,  or  more  properly  the  sporangium  or  spore-case.  This  is 
rarely  (in  Andraia)  dehiscent  into  four  valves,  or  irregularly  rup- 
tured (in  Phascum,  &c).  It  usually  opens  by  a  lid  {ppercidum)  : 
beneath  the  lid  and  arising  from  the  mouth  of  the  capsule  are  com- 
monly either  one  or  two  rows  of  rigid  processes  (collectively  the 


CRYPTOGAHOUS    OK    FLOWERLESS    PLANTS. 


503 


peristome),  which  are  always  some  multiple  of  four:  those  of  the 
outer  row  are  called  teeth,  of  the  inner,  cilia.  The  spores  which  fill 
the  cavity  commonly  appear  like  an  impalpable  greenish  powder. 
The  pedicel  continued  through  the  capsule  forms  the  columella :  en- 
larged under  the  capsule  it  sometimes  forms  an  apophysis.     The 


calyptra  separating  early  at  its  base  is  carried  up  on  the  apex  of  the 
capsule  ;  if  it  splits  on  one  side,  it  is  hood-shaped  or  cuculliform,  if 
not,  it  is  mitre-shaped  or  mitriform.  The  particular  structure  of  all 
our  genera  of  Mosses,  and  of  the  following  order,  is  illustrated  in 
the  plates  of  the  Manual  of  the  Botany  of  the  Northern  United 
States  ;  to  which  the  student  is  referred  for  details. 

973.  Ofll.  HepatiCfB  {Liverworts).  Frondose  or  Moss-like  plants, 
of  a  loose  cellular  texture,  usually  procumbent  and  emitting  rootlets 
from  beneath ;  the  calyptra  not  separating  from  the  base,  but  usually 
rupturing  at  the  apex ;  the  sporangium  or  capsule  not  opening  by  a 


FIG.  1300.  Mnium  cuspidatum.  1301.  The  calyptra  detached  from  the  spore-case.  1302. 
Magnified  spore-case,  from  which  the  lid  or  operculum,  1303,  has  been  removed,  showing  the 
peristome.  1304.  A  portion  of  the  annulus  or  ring  under  the  lid,  more  magnified.  1305.  A 
portion  of  the  outer  and  inner  peristome,  highly  magnified.  1306.  The  so-called  flowers  in  a 
young  state,  consisting  of  the  pistillidia  $,  and  the  antheridia  <j ,  with  some  cellular  jointed 
threads  intermixed  ;  the  involucral  leaves  cut  away.  1307.  One  of  the  antheridia  more  magni- 
fied (with  some  accompanying  cellular  threads),  opening  at  the  apex,  and  discharging  the  con- 
tents. 1308.  Simple  peristome  of  Splachnum  ;  the  teeth  united  in  pairs.  1309.  Double  peris- 
tome of  Hypnum  ;  the  exterior  spreading.  1310.  Physcomitrium  (Gymnostomum)  pyriforme. 
1311.  Its  calyptra,  detached  from,  1312,  the  theca.  1313.  The  lid  removed  from  the  orifice, 
which  is  destitute  of  a  peristome. 


504 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


lid,  containing  spores  usually  mixed  with  elaters  (which  are  thin, 
thread-like  cells,  containing  one  or  two  spiral  fibres,  uncoiling  elas- 
tieally  at  maturity).  Vegetation  sometimes  frondose,  i.  e.  the  stem 
and  leaves  confluent  into  an  expanded  leaf-like  mass ;  sometimes 
foliaceous,  when  the  leaves  are  distinct  from  the  stem,  as  in  true 
Mosses :  the  leaves  are  entire  or  cleft,  two-ranked,  and  often  with  an 
imperfect  or  rudimentary  row  (amphigastrid)  on  the  under  side  of  the 
stem.  The  matured  pistillidium  forms  the  sporangium  or  capsule, 
which  is  either  sessile  or  borne  on  a  long  cellular  pedicel,  and  de- 
hiscent by  irregular  openings,  by  teeth  at  its  apex,  or  lengthwise  by 
two  or  four  valves.  The  perianth  is  a  tubular  organ  enclosing 
the  calyptra,  which  directly  includes  the  pistillidium.  Surrounding 
the  perianth  are  involucral  leaves  of  particular  forms.  The  an- 
theridia  in  the  foliaceous  species  are  situated  in  the  axils  of  peri- 
gonial  leaves. 

974.  Sllbord.  RicciacCtU  consists  of  a  few  chiefly  floating  plants,  root- 
ing from  beneath,  with  their  fructification  immersed  in  the  frond,  the 
sporangium  bursting  irregularly.  No  involucre  nor  elaters.  —  Ex. 
Biccia. 


975.  Sllbord.  AlltllOCerotefE.  Terrestrial  frondose  annuals,  with  the 
fruit  protruded  from  the  upper  surface  of  the  frond.  Perianth  none. 
Sporangium  pod-like,  one-  or  two-valved,  with  a  free  central  colu- 
mella.    Elaters  none  or  imperfect. 

976.  Sllbord.  Mareliailtiaceec  {True  Liverworts).  Frondose  and  ter- 
restrial perennials,  growing  in  wet  places,  with  the  fertile  receptacle 
raised  on  a  peduncle,  capitate  or  radiate,  bearing  pendent  calyptrate 

FIG.  1314, 1315.  Riccia  natans,  about  the  natural  size.  1316.  Magnified  section  through 
the  thickness  of  the  frond,  showing  the  immersed  sporangia  ;  one  of  which  has  burst  through 
and  left  an  effete  cavity.  1317.  Magnified  vertical  section  of  one  of  the  sporangia,  with  the 
contained  spores.  1318.  Sporangium  torn  away  from  the  base,  and  a  quaternary  group  of 
spores,  united  and  separated. 


CRYPTOGAMOU8    OR    FLOWERLESS    PLANTS. 


505 


sporangia  from  the  under  side :  these  open  variously,  but  are  not 
four-valved.     Elaters  with  two  spiral  fibres. 


977.  Subord.  Juilgermaimiacesc.  Frondose  or  mostly  foliaceous 
plants  ;  with  the  sporangium  dehiscent  into  four  valves,  and  the 
spores  mixed  with  elaters. 


Class  V.    Thallophytes. 

Vegetables  composed  of  parenchyma  alone,  forming  a  mass  or 
stratum  (thallus,  109,  727),  or  consisting  of  a  congeries  of  cells,  or 
even  of  separate  cells,  never  exhibiting  a  marked  distinction  into 
root,  stem,  and  foliage,  or  into  axis  and  leaves. 

978.  Ord.  Liclienes  {Lichens)  form  the  highest  grade  of  this  lower 
series.  They  consist  of  flat  expansions,  which  are  rather  crustaceous 
than  foliaceous  ;  while  some  are  nearly  pulverulent.  In  several  the 
vegetation  rises  into  a  kind  of  axis,  or  imitates  stems  and  branches  ;  as 
in  the  Cladonia  coccinea,  which  abounds  on  old  logs  (Fig.  1327)  ;  or 
in  Cladonia  rangiferina,  the  Reindeer  Moss ;  also  in  Usnea,  where 
it  forms  long,  gray  tufts,  hanging  from  the  boughs  of  old  trees  in  our 
Northern  forests.  Lichens  are  never  aquatic,  but  grow  on  the  ground, 
on  the  bark  of  trees,  or  on  exposed  rocks,  to  which  the  proper  rock- 
Lichens  adhere  by  their  lower  surface,  with  great  tenacity,  while  by 


FIG.  1319.  Steetzia  Lyellii,  with  the  young  fructification  still  included  in  the  tubular  peri- 
anth. 1320.  Dehiscent  sporangium  of  a  Jungermannia,  on  its  fruit-stalk,  with  some  of  the 
leaves  at  its  base,  magnified  enough  to  exhibit  its  cellular  structure.  1321.  Two  elaters  from 
the  same  (a,  in  an  entire  state  ;  b,  with  only  the  threads  remaining),  and  some  spores,  highly 
magnified. 

43 


506 


ILLUSTRATIONS    OF    THE    NATURAL    ORDERS. 


the  upper  they  draw  their  nourishment  directly  from  the  air.  The 
fructification  is  in  crips,  or  shields  (apothecia),  resting  on  the  surface 
of  the  thallus,  or  more  or  less  immersed  in  its  substance,  or  else  in 
pulverulent  spots  scattered  over  the  surface.  A  magnified  section 
through  an  apothecium  (Fig.  1824)  brings  to  view  a  stratum  of 
elongated  sacs  (asci),  with  filaments  intermixed,  as  seen  detached 
and  highly  magnified  at  Fig.  1325.  Each  ascics,  or  sac,  contains  a 
few  spores :  these  divide  into  two,  which,  however,  generally  remain 


coherent.  For  a  description  of  the  Lichens  of  this  country,  the 
student  is  referred  to  Professor  Tuckerman's  Synopsis  of  the  Li- 
chenes  of 'New  England,  the  other  Northern  States,  fyc.  and  to  his 
Lichenes  Amer.  Sept.  Exsiccati,  illustrating  them  by  named  speci- 
mens. 


FIG.  1322.  A  stone  upon  which  several  Lichens  are  growing,  such  as  (passing  from  left  to 
right)  Parmelia  conspersa,  Sticta  miniata,  Lecidea  geographica  (so  called  from  its  patches  re- 
sembling the  outline  of  islands,  &c.  on  maps),  &c,  &c.  1323.  Piece  of  the  thallus  of  Parme- 
lia conspersa,  with  a  section  through  an  apothecium.  1324.  Section  of  a  smaller  apothecium, 
more  magnified.  1325.  Two  asci  and  their  contained  spores,  with  the  accompanying  filaments, 
highly  magnified.  1326.  Section  of  a  piece  of  the  thallus  of  Sticta  miniata,  showing  the  im- 
mersed apothecia.  1327.  Cladonia  coccinea,  bearing  its  fructification  in  rounded  red  masses 
on  the  edges  of  a  raised  cup. 


CRYPTOGAMOUS    OR    FLOWERLESS    PLANTS.  507 

979.  Ord,  Fungi  {Mushrooms,  Moulds,  S>-c.)  are  parasitic  (150,  153) 
flowerless  plants,  either  in  a  strict  sense,  as  living  upon  and  draw- 
ing their  nourishment  from  living,  though  more  commonly  languish- 
ing, plants  and  animals,  or  else  as  appropriating  the  organized  mat- 
ter of  dead  and  decaying  animal  and  vegetable  bodies.  Hence  they 
fulfil  an  office  in  the  economy  of  creation  analogous  to  that  of  the 
infusory  animalcules.  Those  Fungi  which  produce  Rust,  Smut, 
Mildew,  &c.  are  of  the  first  kind  ;  those  which  produce  Dry-rot,  &e. 
hold  a  somewhat  intermediate  place  ;  and  Mushrooms,  Puff-balls, 
&c.  are  examples  of  the  second.  Fungi  are  consequently  not  only 
destitute  of  anything  like  foliage,  but  also  of  the  green  matter,  or 
chlorophyll,  which  appears  to  play  an  essential  part  in  vegetable 
assimilation.  A  full  account  of  the  diversified  modifications  of  struc- 
ture that  Fungi  display,  and  of  the  remarkable  points  in  their 
economy,  would  require  a  large  volume.  We  will  notice  three  sorts 
only,  which  may  represent  the  highest,  and  nearly  the  lowest,  forms 
of  this  vast  order  or  class  of  plants.  They  all  begin  (in  germina- 
tion or  by  offsets)  with  the  production  of  copious  filamentous  threads, 
or  series  of  attenuated  cells,  appearing  like  the  roots  of  the  fungus 
that  arises  from  them  (Fig.  1328,  1330),  and  to  a  certain  extent 
performing  the  functions  of  roots  :  this  is  called  the  mycelium,  and 
is  the  true  vegetation  of  Fungi.  The  subsequent  developments 
properly  belong  to  the  fructification,  or  are  analogous  to  tubers, 
rhizomas,  &c.  In  one  part  of  the  order,  the  masses  that  arise,  of 
various  definite  shapes,  and  often  attaining  a  large  size,  contain  in 
their  interior  a  multitude  of  asci  (Fig.  1329),  enclosing  simple  or 
double  sporules,  just  as  in  Lichens.  The  esculent  Morel  has  this 
kind  of  fructification  ;  as  well  as  the  less  conspicuous  Sphaeria  (Fig. 
1328),  which  is  in  other  respects  of  a  lower  grade.  The  Agarics, 
like  the  Edible  Mushroom  (Fig.  1330),  produce  their  spores  in  a 
different  way.  Rounded  tubercles  appear  on  the  mycelium ;  some 
of  these  rapidly  enlarge,  burst  an  outer  covering  which  is  left  at  the 
base  (the  volva,  or  wrapper),  and  protrude  a  thick  stalk  (stipes), 
bearing  at  its  summit  a  rounded  body  that  soon  expands  into  the 
pileus,  or  cap.  The  lamellce,  or  gills  (Jtymenium),  that  occupy  its 
lower  surface,  consist  of  parallel  plates  (Fig.  1331),  which  bear 
naked  sporules  over  their  whole  surface.  A  careful  inspection  with 
the  microscope  shows  that  these  sporules  are  grouped  in  fours  ;  and 
a  view  of  a  section  of  one  of  the  gills  shows  their  true  origin  (Fig. 
1332).     Certain  of  the  cells  (basidia),  one  of  which  is  shown  more 


508 


ILLUSTRATIONS    OP    THE    NATURAL    ORDERS. 


magnified  at  Fig.  1333,  produce  four  small  cells  at  their  free  sum- 
mit, apparently  by  gemmation  and  constriction  :  these  are  the  spores. 
It  is  maintained  that  the  larger  intermingled  cells,  (of  which  one  is 
shown  at  Fig.  1332,  a,)  filled  with  an  attenuated  form  of  matter,  are 
the  analogues  of  antheridia.  The  lowest  Fungi  produce  from  their 
mycelium  only  simple  or  branching  series  of  cells  (Fig.  92-94). 
The  mycelium  itself  either  ramifies  through  decaying  organized 
matter,  as  the  Moulds,  &c. ;  or  else  —  like  the  Blight  and  Rust  in 
grain,  and  the  3fuscardine  so  destructive  to  silkworms,  and  others 


so  destructive  to  the  Grape,  the  Potato,  &c.  —  it  attacks  and  spreads 
throughout  living  tissues,  often  producing  great  havoc  before  its 
fructification  is  revealed  at  the  surface.  Sometimes  the  last  cells  of 
the  stalks  swell  into  a  vesicle,  in  which  the  minute  sporules  are 
formed  ;  as  in  Fig.  92.  Sometimes  the  branching  stalks  bear  single 
sporules,  like  a  bunch  of  grapes  (Fig.  94),  or  long  series  of  cells,  or 

FIG.  1328.  Sphseria  rosella.  1329.  Asci  from  its  interior,  containing  sporules,  highly  mag- 
nified. 1330.  Agaricus  campestris,  the  Edible  mushroom,  in  its  various  stages.  1331.  Section 
through  the  pileus,  to  display  the  gills.  1332.  A  small  piece  of  a  slice  through  the  thick- 
ness of  one  of  the  gills,  magnified  ;  showing  the  spores  borue  on  the  summit  of  salient  cells 
of  both  surfaces.  1333.  One  of  the  sporule-bearing  cells,  with  some  subjacent  tissue,  more 
magnified. 


CRYPTOGAMOUS    OR    FLOWERLESS    PLANTS.  509 

sporules,  in  rows,  like  the  beads  of  a  necklace  (Fig.  93),  which, 
separating,  become  the  rudiments  of  new  plants. 

980.  Ol'd.  AlgSB  (Seaioeeds).  This  vast  order  consists  of  aquatic 
plants,  for  the  most  part  strictly  so,  but  some  grow  in  humid  ter- 
restrial situations.  The  highest  forms  are  the  proper  Seaweeds 
(  Wrack,  Tang,  Dulse,  Tangle,  &c.)  ;  "  some  of  which  have  stems  ex- 
ceeding in  length  (although  not  in  diameter)  the  trunks  of  the  tallest 
forest-trees,  while  others  have  leaves  (fronds)  which  rival  in  expan- 
sion those  of  the  Palm."  "  Others  again  are  so  minute  as  to  be 
wholly  invisible,  except  in  masses,  to  the  naked  eye,  and  require  the 
highest  powers  of  our  microscopes  to  ascertain  their  form  and  struc- 
ture." Some  have  the  distinction  of  steins  and  fronds ;  others  show 
simple  or  branching  solid  stems  only  ;  and  others  flat  foliaceous  ex- 
pansions alone  (Fig.  95),  either  green,  olive,  or  rose-red  in  hue. 
From  these  we  descend  by  successive  gradations  to  simple  or 
branching  series  of  cells  placed  end  to  end,  such  as  the  green  Con- 
fervas of  our  pools,  and  many  marine  forms  :  we  meet  with  congeries 
of  such  cells  capable  of  spontaneous  disarticulation,  each  joint  of 
which  becomes  a  new  plant,  so  that  the  organs  of  vegetation  and  of 
fructification  become  at  length  perfectly  identical,  both  reduced  to 
mere  cells  ;  and  finally,  as  the  last  and  lowest  term  of  possible  vege- 
tation, we  have  the  plant  reduced  to  a  single  cell,  giving  rise  to  new 
ones  in  its  interior,  each  of  which  becomes  an  independent  plant 
(Fig.  79  -  83,  18  -  22).  Our  Alga?  should  be  studied  by  the  aid  of 
the  admirable  Nereis  Boreali-Americana,  or  History  of  the  Marine 
AlgcB  of  North  America,  by  Professor  Harvey,  published  by  the 
Smithsonian  Institution.  For  the  fresh-water  species  we  have  no 
American  work.  The  main  divisions  of  Alga?  are  into  the  following 
suborders. 

981.  Subord.  MelanospermCflB,  or  FucaceSE,  the  Olive-green  Seaweeds; 
having  dark-colored  spores  and  generally  an  olive-green  color,  such 
as  the  common  Rockweed,  Gulfweed,  &c.  The  fertilization  of  these 
spores  has  already  been  described  (661). 

982.  Subord.  Rliodosperiliere,  or  Floridefe,  the  Hose-red  Seaioeeds,  so 
called  from  their  prevailing  color.  These,  the  most  beautiful  of 
Alga?  (including  the  Dulse,  Laver,  &c.)  have  two  kinds  of  spores ; 
one  large,  simple,  and  superficial ;  the  others  dispersed  through  the 
interior  of  the  frond,  and  formed  four  together  in  a  mother  cell. 

983.  Sllbord.  Clllorospermerc,  the  Bright-green  Alga;,  the  spores  and 
the  vegetation  of  which  are  generally  of  a  lively  green  hue,  are  more 

43* 


510 


ILLUSTRATIONS  OF  THE  NATURAL  ORDERS. 


simple  in  structure,  and  include  the  fresh-water  kinds  generally,  as 
well  as  numerous  marine  species  ;  among  them  those  of  single  rows  of 
cells,  or  of  single  cells  (100-105,  656  -  660).  Some  of  these  fruc- 
tify by  conjugation  (655  —  657),  as  is  the  case  in  those  simplified 
forms  which  compose  the 

984.  Sllbord.  DcsmidiaceSB,  which  are  microscopic  and  infusory  green 
Alga3  of  single  cells  (Fig.  100,  655),  often  of  crystal-like  forms,  in- 
vested with  mucus,  and  belonging  to  fresh  water.  They  multiply 
largely  by  division,  but  strictly  propagate  only  by  conjugation.  Many 
of  them  have  long  been  claimed  for  the  animal  kingdom,  or  es- 
teemed of  ambiguous  nature,  on  account  of  the  free  movements 
they  exhibit ;  but  this  affords  no  real  distinc- 
tion. (Chap.  XII.,  XIII.)  More  ambiguous 
still,  and  on  the  lowest  confines  of  the  vegeta- 
ble kingdom,  are  those  minute  vegetables,  as 
they  doubtless  are,  which  constitute  the 

985.  Subord.  Diatomaccrc.  These  differ 
from  the  last  chiefly  in  the  brown  instead  of 
green  color  of  their  contents,  in  the  siliceous 
and  durable  nature  of  their  cell-wall,  and  in 
being  natives  of  salt  instead  of  fresh  water. 
Their  movements,  as  they  break  up  from 
their  connections,  are  still  more  vivid  and 
varied.  Some  are  fixed ;  others  are  free. 
Some  are  extremely  minute :  others  form 
clusters  of  cells  of  considerable  size.  All 
require  a  compound  microscope  for  their 
study,  and  a  full  treatise  is  needed  to  do  them 
justice. 

986.  Ord.  Characese.  The  Chara  Family 
consists  of  a  few  aquatic  plants,  which  have 
all  the  simplicity  of  the  lower  Algae  in  their 

vegetation,  being  composed  of  simple  tubular  cells  placed  end  to 
end,  and  often  with  a  set  of  smaller  tubes  applied  to  the  surface  of 
the  main  one  (Fig.  1335,  1336).  Hence  they  have  been  placed 
among  Algae.  But  their  fructification  is  of  a  higher  order.  It  con- 
sists of  two  kinds  of  bodies  (both  shown  in  Fig.  1335),  of  which 

FIG.  1334.  Branch  of  the  common  Chara,  nearly  the  natural  size.  1335  A  portion  magni- 
fied, showing  the  lateral  tubes  enclosing  a  large  central  one  (a  portion  more  magnified  at  1336) ; 
also  a  spore,  invested  by  a  set  of  tubes  twisted  spirally  around  it ;  and  the  antheridium  borne 
at  its  base. 


THE    ARTIFICIAL    SYSTEM    OF    LINN.EUS.  511 

the  smaller  (and  lower)  contains  antheridia  of  curious  structure, 
provided  with  slender  and  active  spermatozoids,  while  the  upper 
and  larger  is  a  sporocarp,  formed  of  a  budding  cluster  of  leaves 
wrapped  around  a  nucleus,  which  is  a  spore  or  sporangium.  The 
order  might  perhaps  have  been  introduced  between  the  Equise- 
tacere  (to  which  the  verticillate  branches  show  some  analogy)  and  the 
Hydropterides  ;  but  its  true  position  is  hard  to  determine. 


CHAPTER     IV. 

OF   THE   ARTIFICIAL    SYSTEM    OF    LINN.EUS. 

987.  The  difference  in  principle  between  an  artificial  and  a  natu- 
ral system  of  classification  has  already  been  indicated  (715).  No 
one  better  understood  this  than  Linnceus,  when,  finding  it  impossible 
in  his  day  to  make  a  natural  classification  available  for  ordinary  use, 
he  proposed,  as  a  temporary  substitute,  the  elegant  artificial  scheme 
which  bears  his  name.  As  this  system  is  identified  with  the  history 
of  the  science,  which  in  its  time  it  so  greatly  promoted,  and  as  most 
systematic  works  have  until  recently  been  arranged  upon  its  plan,  it 
is  still  necessary  for  the  student  to  understand  it.  Its  principles  are 
so  simple,  that  a  brief  space  will  amply  suffice  for  its  explanation. 

988.  It  must  be  kept  in  mind,  that  an  artificial  scheme  does  not 
attempt  to  fulfil  all  the  conditions  of  natural-history  classification. 
Its  principal  object  is  to  furnish  an  easy  mode  of  ascertaining  the 
names  of  plants  ;  their  relationships  being  only  so  far  expressed  as 
the  plan  of  the  scheme  admits.  All  higher  considerations  are  of 
course  sacrificed  to  facility.  In  the  Linnsean  classification,  the 
species  of  a  genus  are  always  kept  together,  whether  or  not  they  all 
accord  with  the  class  or  order  under  which  they  are  placed.  Its 
lower  divisions,  therefore,  namely,  the  genera  and  species,  are  the 
same  as  in  a  natural  system.  But  the  genera  are  arranged  in  arti- 
ficial classes  and  orders,  founded  on  some  single  technical  character, 
and  have  no  necessary  agreement  in  any  other  respect ;  just  as 
words  are  alphabetically  arranged  in  a  dictionary,  for  the  sake  of 
convenience,  although  those  which  stand  next  each  other  have,  it 
may  be,  nothing  in  common  beyond  the  initial  letter. 


512  THE    ARTIFICIAL    SYSTEM    OF    LINNAEUS. 

989.  The  classes  and  orders  Linnaeus  founded  entirely  upon  the 
number,  situation,  and  connection  of  the  stamens  and  pistils ;  the 
office  and  importance  of  which  he  had  just  set  in  a  clear  light. 

990.  The  classes,  twenty-four  in  number,  were  founded  upon 
modifications  of  the  stamens,  and  have  names  of  Greek  derivation 
expressive  of  their  character.  The  first  eleven  comprise  all  plants 
with  perfect  flowers,  and  with  a  definite  number  of  equal  and  un- 
connected stamens.  They  are  distinguished  by  the  absolute  number 
of  these  organs,  and  are  designated  by  names  compounded  of  Greek 
numerals  and  the  word  andria  (from  uvrjp),  which  is  used  meta- 
phorically for  stamen,  as  follows  :  — 

Class  1.  Monandria  includes  all  such  plants  with  one  stamen  to 
the  flower ;  as  in  Hippuris. 

2.  Diandria,  those  with  two  stamens,  as  in  the  Lilac. 

3.  Triandria,  with  three  stamens,  as  in  the  Valerian,  &c. 

4.  Tetrandria,  with  four  stamens,  as  in  the  Scabious. 

5.  Pentandria,  with  five  stamens,  the  most  frequent  case. 

6.  Hexandria,  with  six  stamens,  as  in  the  Lily  Family,  &c. 

7.  Heptandria,  with  seven  stamens,  as  in  Horsechestnut. 

8.  Octandria,  with  eight  stamens,  as  in  Evening  Primrose,  &c. 

9.  Enneandria,  with  nine  stamens,  as  in  the  Rhubarb. 

10.  Decandria,  with  ten  stamens,  as  in  Rhododendron. 

11.  Dodec andria,  with  twelve   stamens,  as  in  Asarum  and 

the  Mignonette ;  extended  also  to  include  those  with 
from  thirteen  to  nineteen  stamens. 

991.  The  two  succeeding  classes  include  plants  with  perfect  flow- 
ers, having  twenty  or  more  unconnected  stamens,  which,  in 

12.  Icosandria,  are  inserted  on  the  calyx  (perigynous,  467), 

as  in  the  Rose  Family ;  and  in 

13.  Polyandria,  on  the  receptacle  (hypogynous,  466),  as  in 

the  Buttercup,  Anemone,  &c. 

992.  Their  essential  characters  are  not  indicated  by  their  names ; 
the  former  merely  denoting  that  the  stamens  are  twenty  in  number ; 
the  latter,  that  they  are  numerous.  —  The  two  following  depend  upon 
the  relative  length  of  the  stamens,  namely, 

14.  Did  yn  ami  a,  including  those  with  two  long  and  two  short 

stamens  (Fig.  407)  ;  and 

15.  Tetrad ynamia,  those  with  four  long  and  two  short  sta- 

mens, as  in  Cruciferous  flowers  (Fig.  406). 


THE   ARTIFICIAL    SYSTEM   OF   LINN^US.  513 

998.  Their  names  ai'e  Greek  derivatives,  signifying  in  the  former 
that  two  stamens,  and  in  the  latter  that  four  stamens,  are  most  pow- 
erful. —  The  four  succeeding  are  founded  on  the  connection  of  the 
stamens: — 

16.  Monadelpiha   (meaning  a  single  fraternity),  with  the 

filaments  united  in  a  single  set,  tube,  or  column,  as  in 
all  the  Mallow  Family,  &c. 

17.  Diadelphia  (two  fraternities),  with  the  filaments  united 

in  two  sets  or  parcels. 

18.  Polyadelphia  (many  fraternities),  with   the  filaments 

united  in  more  than  two  sets  or  parcels. 

19.  Syngenesia  (from  Greek  Avords  signifying  to  grow  to- 

gether), with  the  anthers  united  in  a  ring  or  tube,  as  in 
all  Compositaj  (844). 

994.  The  next  class,  as  its  name  denotes,  is  founded  on  the  union 
of  the  stamens  to  the  style :  — 

20.  Gynandria,  with  the  stamens  and  styles  consolidated,  as 

in  the  Orchis  Family  (Fig.  468). 

995.  In  the  three  following  classes,  the  stamens  and  pistils  are 
found  in  separate  blossoms :  — 

21.  Moncecia  (one  household)  includes  all  plants  where  the 

stamens  and  pistils  are  in  separate  flowers  on  the  same 
individual ;  as  in  the  Oak,  &c. 

22.  Diozcia  (two  households),  where  they  occupy  separate 

flowers  on  different  individuals ;  as  in  the  Willow,  Pop- 
lar, Moonseed  (Fig.  413,  414),  &c. 

23.  Polygamia,  where  the  stamens  and  pistils  are  separate 

in  some  flowers  and  united  in  others,  either  on  the 
same,  or  two  or  three  different  plants ;  as  in  most 
Maples. 

996.  The  only  remaining  class, 

24.  Cryptogamia,  is  inferred  to  have  concealed  stamens  and 

pistils  (as  the  name  imports),  or  the  analogues  of  these 
organs,  and  includes  the  Ferns,  Mosses,  Lichens,  &c., 
which  are  now  commonly  termed  Cryptogamous  or  Flow- 
erless  Plants  (651). 

997.  The  characters  of  the  classes  may  be  presented  at  a  single 
view,  as  in  the  subjoined  analysis  :  — 


514 


THE    ARTIFICIAL    SYSTEM    OF    LINN.EUS. 


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THE    ARTIFICIAL    SYSTEM    OP   LIXXiEUS.  515 

998.  The  orders,  in  the  first  thirteen  classes  of  the  Linnrean  ar- 
tificial system,  depend  on  the  number  of  styles,  or  of  the  stigmas 
when  the  styles  are  wanting ;  and  are  named  by  Greek  numerals 
prefixed   to   the   word   gynia,   used    metaphorically   for   pistil,   as 

follows :  — 

Order  1.  Monogyxia  embraces  all  plants  of  any  of  the  first  thir- 
teen classes,  with  one  style  to  each  flower. 

2.  Digynia  embraces  those  with  two  styles. 

3.  Trigynia,  those  with  three  styles. 

4.  Tetragynia,  those  with  four  styles. 

5.  Pextagyxia,  those  with  five  styles. 

6.  Hexagynia,  those  with  six  styles. 

7.  Heptagyxia,  those  with  seven  styles. 

8.  Octogyxia,  those  with  eight  styles. 

9.  Exxeagyxia,  those  with  nine  styles. 

10.  Decagyxia,  those  with  ten  styles. 

11.  Dodecagyxia,  those  with  eleven  or  twelve  styles. 

12.  Polygyxia,  those  with  more  than  twelve  styles. 

999.  The  orders  of  class  14,  Didynamia,  are  only  two ;  namely, 

1.  Gy.mxospermia,  meaning  seeds  naked,  the  achenia-like 

fruits  having  been  taken  for  naked  seeds. 

2.  Axgiospermia,  with  the  seeds  evidently  in  a  seed-vessel 

or  pericarp. 

1000.  The  15th  class,  Tetradynamia,  is  also  divided  into  two  or- 
ders, which  are  distinguished  merely  by  the  form  of  the  pod  :  — 

1.  Siliculosa;  the  fruit  a  silicle  (G21),  or  short  pod. 

2.  Siliquosa  ;  fruit  a  silique  (620),  or  more  or  less  elon- 

gated pod. 

1001.  The  orders  of  the  16th,  17th,  18th,  20th,  21st,  and  22d 
classes  depend  merely  on  the  number  of  stamens  ;  that  is,  on  the 
characters  of  the  first  thirteen  classes,  whose  names  they  likewise 
bear :  thus, 

Order  1.  Moxaxdria,  with  one  stamen  ;  2.  Diaxdria,  with  two 
stamens ;  and  so  on. 

1002.  The  orders  of  the  19th  class,  Syngenesia,  are  six  ;  namely, 
1.  Polygamia  ^equalis,  where  the  flowers   are  in  heads 

(compound  flower,  394),  and  all  perfect. 


516  THE    ARTIFICIAL    SYSTEM    OF    LINNJEUS. 

2.  Polygamia  superfltja,  the  same  as  the  last,  except  that 

the  rays,  or  marginal  flowers  of  the  head,  are  pistillate 
only. 

3.  Polygamia  frustranea,  those  with  the  marginal  flowers 

neutral  (Fig.  324,  325),  the  others  perfect. 

4.  Polygamia  necessaria,  where  the  marginal  flowers  are 

pistillate   and   fertile,  and  the  central,  staminate   and 
sterile. 

5.  Polygamia  segregata,  where  each  flower  of  the  head 

has  its  own  proper  involucre. 

6.  Monogamia,  where  solitary  flowers  (that  is,  not  united 

into  a  head)  have  united  anthers,  as  in  Lobelia. 

1003.  The  23d  class,  Polygamia,  has  three  orders,  founded  on  the 
characters  of  the  two  preceding  classes  ;  namely, 

1.  Moncecia,  where  both  separated  and  perfect  flowers  are 

founded  in  the  same  individual. 

2.  Dicecia,  where  they  occupy  different  individuals. 

3.  Tricecia,  where  one  individual  bears  the  perfect,  another 

the  staminate,  and  a  third  the  pistillate  flowers. 

1004.  The  orders  of  the  24th  class,  Cryptogarnia,  are  natural  or- 
ders, and  therefore  not  definable  by  a  single  character.     They  are, 

1.  Filices,  the  Ferns. 

2.  Musci,  the  Mosses. 

3.  Alg^e,  which,  as  left  by  Linnaeus,  comprised  the  Hepaticoe, 

Lichens,  &c,  as  well  as  the  Seaweeds. 

4.  Fungi,  Mushrooms,  &c. 


APPENDIX. 


Of  the  Signs  and  Abreviations  employed  in  Botanical  Writings. 

LinnvEus  adopted  the  following  signs  for  designating  the  duration  of  a 
plant,  viz. :  — 

(2)  An  annual  plant. 
g  A  biennial  plant. 
21  A  perennial  herb. 
\  A  shrub  or  tree. 

Among  the  signs  recently  introduced,  the  following  have  come  into 
general  use :  — 

O  A  monocarpic  (once-flowering)  plant,  whether  annual  or  biennial. 

Q  An  annual  plant. 

©  A  biennial  plant. 

21  A  perennial  herb. 

\  A  plant  with  a  woody  stem. 

g  A  staminate  flower,  or  plant. 

9  A  pistillate  flower,  or  plant. 

£  A  perfect  flower,  or  a  plant  bearing  perfect  flowers. 
!   The  exclamation  point  is  employed  as  the  counterpart  of  the  note  of 
interrogation.     When  it  follows  the  name  of  an  author  appended  to 
the  name  of  a  plant,  it  imports  that  an  authentic  specimen  of  the 
plant  in  question,  under  this  name,  has  been  examined  by  the  writer: 
when  it  is  appended  to  a  locality,  it  signifies  that  the  writer  has  seen  or 
collected  specimens  of  the  plant  from  that  locality,  &c. 
?  The  note  of  interrogation  is  employed  to  denote  doubt  or  uncertain- 
ty ;  and  is  affixed  either  to  a  generic  or  specific  name,  or  to  that  of  an 
author  or  locality  cited. 
*  As  used  by  De  Candolle,  indicates  that  a  good  description  is  found  at 
the  reference  to  which  it  is  appended.     It  is  not  in  common  use. 
44 


518  APPENDIX. 

Those  abbreviations  of  the  names  of  organs  which  are  commonly  em- 
ployed, such  as  Cal.  for  calyx,  Cor.  for  corolla,  Fl.  for  flower,  Fr.  for 
fruit,  Gen.  for  genus,  Hob.  for  habitat,  Herb,  for  herbarium,  Hort.  for 
garden,  Mus.  for  Museum,  Orel,  for  order,  Had.  (Radix)  for  root,  Syn.  for 
synonymy,  Sp.  or  Spec,  for  species,  Var.  for  variety,  &c,  scarcely  require 
explanation. 

V.  sp.  denotes,  in  general  terms,  that  the  writer  has  seen  the  plant  under 

consideration. 
V.  s.  c.  (Vidi  siccam  cidtani),  that  a  dried  specimen  of  a  cultivated  plant 

has  been  examined. 
V.  s.  s.  ([Vidi  siccapi  spontaneani),  that  a  dried  specimen  of  the  wild 

plant  has  been  examined. 
V.  v.  c.  (Vidi  vivam  cultani),  that  the  living  cultivated  plant  has  been 

under  examination. 
V.  v.  s.  (Vidi  vivam  spontaneani),  that  the  wild  plant  has  been  examined 
in  a  living  state. 

The  names  of  authors,  when  of  more  than  one  syllable,  are  commonly 
abridged  by  writing  the  first  syllable,  and  the  first  letter  or  the  first  con- 
sonant of  the  second.  Thus,  Linn.,  or  L.,  is  the  customary  abbreviation 
for  Linnaeus ;  Juss.  for  Jussieu ;  Willd.  for  Willdenow ;  Muld.  for  Muh- 
lenberg;  Hfichx.  for  Miehaux;  Rich,  for  Richard;  De  Cand.,  or  DC, 
for  De  Candolle ;  Hook,  for  Hooker ;  Endl.  for  Endlicher ;  Lindl.  for 
Lindley,  &c. 


Of  Collecting  and  Preserving  Plants. 

1.  The  botanist's  collection  of  specimens  of  plants,  preserved  by  drying 
under  pressure  between  folds  of  paper,  is  termed  a  Hortus  Siccus,  or  com- 
monly an  Herbarium. 

2.  A  complete  specimen  consists  of  one  or  more  shoots,  bearing  the 
leaves,  flowers,  and  fruit ;  and,  in  case  of  herbaceous  plants,  a  portion  of 
the  root  is  also  desirable. 

3.  Fruits  and  seeds  which  are  too  large  to  accompany  the  dried  speci- 
mens, or  which  would  be  injured  by  compression  Avith  sections  of  wood, 
&c,  should  be  separately  preserved  in  cabinets. 

4.  Specimens  for  the  herbarium  should  be  gathered,  if  possible,  in  a  dry 
day  ;  and  carried  either  in  a  close  tin  box,  as  is  the  common  practice,  or 
in  a  strong  portfolio,  containing  a  quire  or  more  of  firm  pajier,  with  a  few 
loose  sheets  of  blotting-paper  to  receive  delicate  plants.  They  are  to 
be  dried  under  strong  pressure,  (but  without  crushing  the  parts,)  between 
dryers  composed  of  six  to  ten  thicknesses  of  bibulous  paper  ;  which  should 
be  changed  daily,  or  even  more  frequently,  until  all  the  moisture  is  ex- 
tracted from  the  plants;  —  a  period  which  varies  in  different  species,  and 


APPENDIX.  519 

with  the  season,  from  two  or  three  days  to  a  week.  All  delicate  speci- 
mens should  be  laid  in  folded  sheets  of  thin  and  smooth  bibulous  paper 
(such  as  tea-paper),  and  such  sheets,  filled  with  the  freshly  gathered 
specimens,  are  to  be  placed  between  the  dryers,  and  so  transferred  entire, 
day  after  day,  into  new  dryers,  without  being  disturbed,  until  perfectly 
dry.  This  preserves  all  delicate  flowers  better  than  the  ordinary  mode  of 
shifting  of  the  papers  which  are  in  immediate  contact  with  the  specimens, 
and  also  saves  much  time  usually  lost  in  transferring  numerous  small 
specimens,  one  by  one,  into  dry  paper,  often  to  the  great  injury  of  the  deli- 
cate corolla,  &c. 

5.  The  dried  specimens,  properly  ticketed  with  the  name,  locality,  &c, 
and  arranged  under  their  respective  genera  and  orders,  are  preserved  in 
the  herbarium,  either  in  separate  double  sheets,  or  with  each  species  at- 
tached by  glue  or  otherwise  to  a  half-sheet  of  strong  white  paper,  with  the 
name  written  on  one  corner.  These  are  collected  in  folios,  or  else  lie  flat 
(as  is  the  best  mode)  in  parcels  of  convenient  size,  received  into  compart- 
ments of  a  cabinet,  with  close  doors,  and  kept  in  a  perfectly  dry  place. 

G.  The  seeds  of  plants  intended  for  cultivation,  which  are  to  be  trans- 
ported to  a  distance  before  being  committed  to  the  earth,  should  first  be 
dried  in  the  sun,  wrapped  in  coarse  paper,  and  preserved  in  a  dry  state. 
They  should  not  be  packed  in  close  boxes,  at  least  so  long  as  there  is  dan- 
ger of  the  retention  of  moisture. 

7.  Roots,  shrubs,  &c,  designed  for  cultivation,  should  be  taken  from  the 
ground  at  the  close  of  their  annual  vegetation,  or  early  in  the  spring  before 
growth  recommences,  and  packed  in  successive  layers  of  slightly  damp  (but 
not  wet)  Peat-moss  (Sphagnum).  Succulent  plants,  however,  such  as 
Cacti,  may  be  packed  in  dry  sand. 

8.  Plants  in  a  growing  state  can  only  be  safely  transported  to  a  consider- 
able distance,  especially  by  sea,  in  the  closely  glazed  cases  invented  by  Mr. 
Ward ;  *  where  they  are  provided  with  the  requisite  moisture,  while  they 
are  sufficiently  exposed  to  the  light. 


*  On  the  Growth  of  Plants  in  Closely  Glazed  Cases,  by  N.  B.  Ward,  F.  L.  S., 
London,  1842.  — Ed.  2,  1853. 


GLOSSARY 

OF  ENGLISH  BOTANICAL  TERMS,  EMPLOYED  IN  BOTANICAL 
DESCRIPTIONS,   COMBINED   WITH  AN 

INDEX. 


[The  numerals  without  any  prefix  refer  to  the  pages  of  the  work :  those  preceded  hy  fig.  to 

figures.] 


A,  privative,  as  the  initial  in  many- 
words  of  Greek  derivation,  signifies 
the  absence  of  the  organ  men- 
tioned; as,  apetalous,  destitute  of 
petals  ;  aphyllous,  leafless.  In 
words  beginning  with  a  vowel  this 
prefix  is  changed  to  an ;  as,  anaxi- 
thous,  flowerless ;  awantherous,  des- 
titute of  anthers. 

Abbreviations.  The  customary  ones 
are  mentioned  on  p.  518. 

Aberrant  (wandering)  :  applied  to  spe- 
cies, genera,  &c.  which  differ  in 
some  respect  from  the  usual  or  nor- 
mal character  of  the  group  they 
belong  to. 

Abietinese,  480. 

Abnormal :  differing  from  the  normal  or 
usual  structure. 

Aboriginal:  strictly  native  ;  indigenous. 

Abortion  :  the  non-formation  or  imper- 
fect formation  of  an  organ,  255. 

Abortive  organs,  258. 

Abrupt :  terminating  suddenly. 

Abruptly  pinnate,  163,  fig.  290. 

Absorption,  80. 

Acanthacese,  447. 

Acanthdcladous :  with  spiny  branches. 

Acanthdphorous :  spine-bearing. 

Acaulescent:  stemless,  or  apparently  so, 
i.  e.  without  a  proper  caulis;  91. 

Accessory :  something  additional. 

Accessory  buds,  98. 

Accessory  fruits,  318. 

Accrescent :  increasing  in  size  after  flow- 
ering, as  the  calyx  of  Physalis. 

44* 


Accrete:  grown  together. 

Acciimbent:    lying   against,    especially 

edgewise    against   another  body; 

326,  390,  fig.  700. 
Acephalous :  headless. 
Aceracea?,  or  Acerinea?,  410. 
Acerose :  needle-shaped,  like  the  leaves 

of  Pines,  &c. ;  166,  fig.  212,  213. 
Acetd  buliform  or  acetabulous  :    saucer- 
shaped. 
Achenium    (pi.   achenia):    a  one-seeded 

seed-like  fruit;  313,  fi£.  566-573. 
Achlamydeous :  destitute   of  calyx  and 

corolla,  261. 
Acids,  56,  195. 
Acicular :     slender    needle-shaped    or 

bristle-shaped. 
Acies :  the  edge  of  a  thing. 
Acindciform :      scymitar-shaped,      like 

some  bean-pods. 
Acines  [acini)  :  the  separate  grains  or 

carpels  of  an  aggregate  fleshy  fruit, 

like  the  raspberry,  as  the  term  is 

now  generally  used ;  classically,  the 

acinus  meant  the  whole  bunch  of 

such  fruits. 
Acotyle'donous :  destitute  of  cotyledons. 
Acrobryous:    budding   from   the    apex 

only ;  same  as 
Acrdgenous :    growing  from  the  apex, 

370. 
Acrogens,  Acrdgenous  plants,  370,  499. 
Acramphibryous :    growing    from   both 

ends  and  over  the  surface. 
Aculeate :  prickly ;  beset  with  prickles 

(aculei)  \  52. 


522 


GLOSSARY    AND    INDEX. 


Aciileolate :  diminutive  of  the  last :  i.  e. 
beset  with  small  or  few  prickles. 

Acuminate :  ending  in  a  narrowed  or 
prolonged  and  tapering  point ;  1 62, 
fig.  268,  239. 

Acutangular :  sharp-angled  ;  as  the 
stems  of  Scirpus  pungens. 

Acute :  merely  sharp-pointed  ;  ending 
by  an  acute  angle  ;  162,  fig.  269. 

Ade/phous  (stamens)  :  joined  by  their 
filaments  or  clustered  into  abrother- 
hood  (adelphia). 

Adherent:  sticking  to,  or,  commonly, 
growing  fast  to,  another  body,  252. 

Adnate:  grown  fast  to,  or  formed  in 
union  with,  another  body,  as  the 
calyx-tube  of  the  Gooseberry  and 
Cranberry  (fig.  391)  to  the  ovary, 
251,  252.  Attached  by  its  whole 
length,  as  the  anther  of  Lirioden- 
dron,  282,  fig.  470,  and  of  Asarum, 
fig.  472. 

Adnation :  the  union  of  heterogeneous 
parts,  250. 

Adpressed,  or  oppressed:  brought  into 
contact  or  nearly,  but  not  united. 

Adscendent,  or  ascending  :  rising  gradu- 
ally upwards,  102. 

Adsurgent,  or  ass  urgent :  rising  upwards. 

Adventitious,  advenlive :  found  out  of 
the  natural  place. 

Adventitious  buds,  82,  98. 

^Equilateral :  equal-sided ;  opposed  to 
oblique. 

Aerial :  growing  in  the  air. 

Aerial  roots,  85. 

Aerophyte :  same  as  Air-plant. 

yEstival:  relating  to  summer. 

^Estivation ;  arrangement  of  floral  or- 
gans in  the  bud,  269. 

Affinity :  true  and  near  relationship  ; 
i.  e.  species  have  affinity  when  they 
resemble  each  other  in  their  prin- 
cipal points  of  structure,  or,  in  other 
words,  are  constructed  throughout 
upon  the  same  particular  plan  or 
t      type.     (See  Analogy.) 

Agamous  or  Agamic :  destitute  of  sexes. 

Agglomerate  or  aggregate :  heaped  or 
crowded  into  a  cluster. 

Aggregate  fruits ,  317. 

Air-cells,  air-passages,  50. 

Air-plants,  87. 

Akenium  or  akene:  see  achenium. 

Ala  (pi.  alai) :  a  wing  ;  the  side  petals 
of  a  papilionaceous  flower ;  253, 
fig.  392,  o. 

Alabdstrum :  a  flower-bud. 

Alar ;  borne  in  the  forks  of  a  stem. 

Alate :  winged  ;  i.  e.  furnished  with  any 
broad  and  thin  adherent  appendage, 
as  the  seeds  of  Trumpet  Creeper, 


fig.  601,  the  leafstalks  of  the  Or- 
ange, Rhus  Copallina,  &c,  and 
the  stem  of  the  common  Thistle. 

Albescent :  whitened,  or  hoary-white. 

Albumen,  a  vegetable  product,  198. 

Albumen  of  the  seed,  76,  322. 

Albuminous  (seeds)  :  furnished  with 
albumen,  323. 

Alburnum:  sapwood,  126. 

Algae,  509. 

Algology :  the  science  relating  to  Algae. 

Alismaccas,  487. 

Alkaloids,  57. 

Alliaceous:  like  the  garlic  or  onion. 

Alliances  :  natural  groups  of  nearly  re- 
lated orders,  374. 

Allspice,  418. 

Almond,  415,  417. 

Alpine:  growing  on  the  higher  parts 
of  the  Alps,  and  in  general  on 
mountains  above  the  limits  of  trees. 

Aloes,  493. 

Alsinea?,  395. 

Alternate  (leaves)  :  situated  one  after 
another,  78,  97,  133.  Petals,  sta- 
mens, «ic.  are  said  to  alternate  with 
adjacent  organs,  when  they  stand 
over  the  intervals  between  them, 
235. 

Alternation  of  parts,  235. 

Alveolate :  honeycombed ;  having  deep 
angular  cavities  separated  by  thin 
partitions,  as  the  receptacle  of  Cot- 
ton-Thistle, fig.  898. 

Amarantacese,  465. 

Amaiyllidacere,  491. 

Anient :  a  catkin  ;  a  peculiar  scaly  spike ; 
213,  fig.  312. 

Amentaceous  :  resembling  or  bearing  cat- 
kins. 

Amnios :  the  embryo-sac,  304. 

Amorphous :  shapeless,  i.  e.  of  no  defi- 
nite or  regular  form. 

Amphibryous :  growing  by  additions 
over  the  whole  periphery. 

Amphicdrpous,  or  amphicdrpic :  produc- 
ing two  kinds  of  fruit ;  as  in  the 
genus  Amphicarpsea,  so  named  on 
this  account. 

Amphigastria  :  the  peculiar  stipule-like 
leaves  of  certain  Hepaticse,  504. 

Amphitropous,  or  amphitropal,  ovule  or 
seed,  300,  fig.  528. 

Amplectant :  embracing. 

Ample'xicaul  (leaves,  &c.) :  clasping  the 
stem  by  a  broad  base  or  insertion. 

Ampulldceous :  shaped  like  an  ampulla 
or  flask-shaped  vessel ;  swelling  out 
at  the  base  or  middle. 

Amygdalece,  415. 

Amylaceous:  composed  of  starch  (dmy- 
lum),  or  resembling  starch. 


GLOSSARY   AND    INDEX. 


523 


Amyloid,  55. 

Amyridaceas,  407. 

Anacardiaceaj,  406. 

Analogy:  resemblance  in  certain  re- 
spects. As  distinguished  from  af- 
finity it  means  resemblance  in  cer- 
tain respects  only,  not  in  the  whole 
plan  of  structure.  Thus  a  Ranun- 
culus is  analogous  to  a  Potentilla, 
but  there  is  no  near  affinity  or  re- 
lationship between  the  two.  And 
the  tendril  of  a  Pea,  that  of  a  Smi- 
lax,  and  that  of  the  Grape- Vine  are 
analogues,  i.  e.  are  analogous  organs, 
but  are  not  homologues  ;  for  the  first 
answers  to  a  leaf,  the  second  to 
stipules,  and  the  third  to  a  stem. 
The  spur  of  a  Larkspur  (fig.  398) 
is  analogous  to  one  of  the  five  spurs 
of  Columbine  (fig.  646),  but  not 
homologous  with  it,  for  the  first  is 
a  sepal,  and  the  second  a  petal. 

Andndrous:  destitute  of  stamens. 

Andntkerous  :  destitute  of  anthers. 

Ananthous :  without  flowers. 

Anastomosing  :  connected  by  cross 
branches  into  a  network,  as  the 
veins  of  animals,  and  the  so-called 
veins  of  reticulated  leaves,  49,  54. 

Andtropous,  or andtropal,  seeds  or  ovules, 
299,  fig.  529. 

Anctpital:  with  two  edges,  as  the  stem 
of  Sisyrinchium  anceps. 

Androzcium:  the  stamens  of  a  flower, 
taken  as  a  whole,  223. 

Androgynous :  bearing  both  stamens  and 
pistils  in  separate  flowers  of  the 
,      same  inflorescence. 

Androphore:  a  column  of  united  stamens, 
or  any  support  on  which  the  sta- 
mens are  raised. 

Androus,  in  words  of  Greek  derivation, 
refers  to  the  stamens  :  see  dian- 
,      droits,  &c. 

Androspores,  335. 

Anfrdctuose  or  anfractuous :  abruptly  bent 
hither  and  thither,  as  the  stamens 
of  Melon,  fig.  467. 

Angiospermia,  515. 

Angiospe'rmous  (Angiospermas,  Angio- 
sperms) :  producing  seeds  in  a  peri- 
carp, 371,  375. 

Angostura  bark,  406. 

Angular  divergence  of  leaves,  135. 

Anise,  426. 

Anisdmerous  (flower)  :  of  unequal  num- 
ber in  the  different  circles  ;  unsym- 
metrical. 

Anisophyllous :  unequal-leaved,  as  when 
the  two  leaves  of  the  same  pair  are 
of  unequal  size. 

Anisoste'monous :  when  the  number  of 


the  stamens  is  different  from  that 
of  the  petals. 

Annual:  lasting  not  above  one  year  or 
one  season,  83. 

Annular :  in  the  form  of  a  ring. 

Annular  ducts,  46. 

Annulate:  marked  with  rings  or  circu- 
,      lar  transverse  lines. 

Annulus:  the  ring  of  the  spore-case  of 
true  Ferns,  501,  fig.  1289:  that  of 
the  mouth  of  the  spore-case  or  cap- 
sule of  Mosses,  503,  fig.  1304. 

Anonacese,  382. 

Anop/iyles  (top-growing  plants,  of  the 
same  meaning  as  Acrogens?),  370, 
502. 

Anteposition,  248. 

Anterior:  as  to  position  in  the  flow- 
er, on  the  side  next  the  bract,  237. 

Anther :  the  pollen-bearing  part  of  a  sta- 
men, 223,  281. 

Aniheridium  (plural,  antheridia),  334, 
502. 

Antherifcrous :  anther-bearing. 

A'nlhesis :  the  time  when  the  flower  opens 
and  performs  its  functions,  or  the 
act  of  expansion  in  a  flower,  271. 

Anthocdipous  fruits,  318. 

Anthoeerdtea3,  504. 

Anthodium :  a  technical  name  for  the 
capitulum  or  head  of  flowers  of  a 
plant  of  the  order  Composita;. 

Antlidlysis :  the  retrograde  metamorpho- 
,      sis  of  a  flower. 

Anthophore:  the  stalk  or  internode  which 
is  sometimes  developed  between  the 
calyx  and  the  corolla,  as  in  Silene, 
.      267,  fig.  432. 

Ant  icons:  anterior,  or  facing  forwards. 

Antitropous,  or  antitropal :  (reversed;) 
applied  to  the  embryo,  it  means  one 
with  the  radicle  pointing  away 
from  the  hilum,  as  in  fig.  600  and 
fig.  606. 

Antrdrse :  directed  upwards  or  forwards. 

Ape'talous :  destitute  of  petals  or  corolla, 
260. 

Aphyllous :  destitute  of  leaves,  at  least 
,     in  the  form  of  foliage. 

Apical:  relating  to  the  apex. 

Apicidate  :  terminating  in  an  abrupt 
short  point  or  tip. 

Apocarpous  pistils  :  those  not  united  into 
one  body  or  compound  pistil,  290. 

Apoeynaceas,  457. 

Apophysis :  any  irregular  enlargement, 
like  that  of  the  spore-case  of  Splach- 
num  and  some  other  Mosses,  503. 

Apothecium  :  the  shield  or  shield-shaped 
fructification  of  most  Lichens,  506. 

Appendix,  appendage :  any  superadded 
part. 


524 


GLOSSARY    AND    INDEX. 


Appendiculate :  having  an  appendage. 

Apple,  416. 

Appresscd :  lying  flat  against,  or  close- 
pressed  together. 

Apricot,  417. 

Apterous :  wingless  ;  having  no  dilated 
border  or  appendages. 

Aquatic :  living  in  water,  either  sub- 
mersed or  raised  partly  out  of  it. 

Aquifoliaceas,  442. 

Araceae,  or  Aroidere,  485. 

Arachnoid,  or  drenose :  cobwebby,  i.  e. 
with  entangled  slender  hairs  look- 
ing like  cobweb. 

Araliacea?,  427. 

Arboreous,  arborescent :  tree-like,  in  size 
or  appearance,  101. 

Archegonium  (pi.  archegonia)  :  the  ana- 
>     logue  in  Mosses  of  the  pistil. 

Arcuate :  curved  like  a  bent  bow. 

Areola,  pi.  areolae :  spaces  marked  out 
on  a  surface. 

Are'olate:  marked  out  into  definite 
spaces. 

Arhizal :  destitute  of  root 

Aril,  arillus :  an  accessory  covering  or 

appendage  of  a  seed  formed  by  a 

growth  from  the  funiculus,  hilum, 

or  placenta  after  the  completion  of 

,     the  ovule,  321,  fig.  603. 

Arillate :  furnished  with  an  arillus. 

Arillode :  a  false  aril,  or  covering  of  the 
seed  appearing  like  an  aril. 

Aristate  :  furnished  with  an  awn  (arista). 

Aristoloehiaceas,  462. 

Arnatto,  392. 

Arre'ct :  pointing  upwards. 

Arrowroot,  481,  490. 

Arrow-shaped,  or  arrow-headed :  see  Sa- 
gittate ;  fig.  252. 

Artichokes,  437. 

Articulated:  jointed,  i.  e.  separating  by 
an  articulation  or  joint,  as  most 
leaves  from  the  stem  in  autumn, 
or  having  the  appearance  of  a  joint, 
92,  163,  173. 

Artificial  classification,  365,  511. 

Artocarpese,  474. 

Ascending :  rising  obliquely  upwards, 
102. 

Ascending  axis,  72,  91. 

Asci:  the  spore-cases  of  certain  Lichens 
and  Fungi,  506,  507. 

Ascidium :  a  pitcher-shaped  or  sac- 
shaped  leaf,  169. 

Asclepiadaceae,  458. 

Ashes  of  plants,  58,  174,  186. 

Aspergilliform  :  shaped  like  an  aspergil- 
lus,  or  brush  used  to  sprinkle  holy 
water,  as  the  stigmas  of  most 
Grasses. 

Assafcetida,  427. 


Assimilation,  19,  21,  61,  177,  190. 

Assurgent :  same  as  ascending. 

Atropous  or  dtropal  (ovules)  :  same  as 
orthotropous,  298. 

Attar  of  Koses,  417. 

Attenuate  :  tapering  gradually  to  a  thin 
or  narrow  extremity. 

Augmentation  of  parts,  242. 

Aurantiaceoe,  401. 

Auriculate :  eared  ;  furnished  with  au- 
ricles or  small  lobes  at  the  base. 

Automatic  movements,  347. 

Ava,  469. 

Avocado  Pear,  467. 

Awl-shaped:  narrow  and  terete,  or  near- 
ly so,  and  tapering  to  a  point ; 
166. 

Awn :  a  bristle-shaped  appendage,  like 
the  beard  of  Barley,  &c. 

Awned :  see  Aristate. 

Axil  {axilla,  the  armpit) :  the  angle  be- 
tween a  leaf  and  the  stem,  on  the 
upper  side,  97. 

Axile,  or  axial :  belonging  to  the  axis, 
,      292. 

Axillary :  belonging  to  or  growing  in 
the  axil. 

Axillary  buds,  &c,  97,  210. 

Axis :  the  stem  and  root,  67,  72  ;  the 
central  line  of  any  body,  as  the 

Axis  of  inflorescence,  211. 

Baccate :  berry-like ;  of  a  fleshy  or  pulpy 

texture  like  a  berry  (bacca),  311. 
Balm  of  Gilead,  &c,  407. 
Balsams,  145,  407,  414,  480. 
Balsamiflua?,  425. 
Balsaminaceai,  403. 
Banner  :  same  as  vexillum,  253. 
Barbate  :  bearded  ;  bearing  tufts,  spots, 

or  lines  of  hairs. 
Bdrbellate :   beset  with  short  and  stiff 

hairs,  like  the  pappus  of  Liatris 

spicata,  &c. 
Barbe'llulate :  a  diminutive  of  the  last. 
Barberry,  384. 
Bark,  120,  126. 
Barley,  498. 
Basal :   belonging  or  relating  to  the 

base  of  an  organ. 
Basellacese,  464. 
Basidia :  cells  of  the  fructification  of 

Mushrooms,  &c,  which  bear  the 

spores,  507. 
Bdsiflxed :  attached  by  the  base. 
Basilar :  seated  on  the  base  of  anything. 
Bassorin,  55. 
Bast,  or  bass,  400  :  bast-cells  or  tissue, 

44,  120. 
Bauerieaa,  425. 
Bavberry,  477. 
Bdellium,  407. 


GLOSSARY   AND    LNDEX. 


525 


Beaked :  ending  in  a  prolonged  narrow 
tip. 

Bearded:  beset  with  hairs,  especially 
stiff  or  long  hairs.  Beard  is  some- 
times used  for  awn. 

Bell-shaped :  having  the  shape  of  a  bell ; 
277,  fig.  456. 

Benzoic  Acid,  Benzoin,  443. 

Berberidaceaj,  384. 

Bergamot,  401. 

Berry :  a  fruit  fleshy  or  pulpy  through- 
out, 311. 

Betel,  469. 

Betulaceae,  477. 

Bi-  (or  bis),  as  a  prefix,  means  twice,  as 
in  the  following  : 

Biaciiminate :  two-pointed. 

Biarticidate :  two-jointed. 

Biauriculate :  two-eared. 

Bibrdeteate  :  with  two  bracts. 

Bibrdcteolate :  with  two  bractlets. 

Bicdllose :  bearing  two  callosities  or  lit- 
tle protuberances. 

Bicipital :  having  two  stalks  or  legs,  as 
the  keel  of  a  papilionaceous  corolla, 
fig.  392. 

Bicdnjugate :  twice-pahed,  as  when  the 
petiole  of  a  compound  leaf  forks 
twice. 

Bicomute :  two-horned. 

Bide'ntate :  having  two  teeth  (not  twice 
dentate  or  doubly  toothed). 

Biennial:  lasting  more  than  one  year, 
but  not  more  than  two  years,  83. 

Bifai-ious :  two-ranked ;  arranged  in  two 
vertical  rows. 

Bifid :  two-cleft  to  the  middle  or  there- 
abouts, 159. 

Biflorous :  two-flowered. 

Bifdliate :  two-leaved. 

Bifdliolate :  of  two  leaflets. 

Bifurcate :  two-forked,  or,  sometimes, 
twice-forked. 

Bigeminate :  twice-paired. 

Bigener :  a  hybrid  between  two  plants 
of  different  genera. 

Bignoniacese,  447. 

Bijugate :  a  pinnate  leaf  with  two  pairs 
of  leaflets. 

Bilabiate:  two-lipped,  255,  258,  278. 

Bildmellate,  or  bildmellar :  of  two  plates 
or  lamella;. 

Bilberry,  439. 

Bildbate,  or  bilobed:  two-lobed,  159. 

Bildcular :  two-celled. 

Binary  :  the  parts  in  twos,  239. 

Binate :  in  twos  ;  produced  or  borne  in 
pairs,  164. 

Binomial  nomenclature  (of  two  names), 
363. 

Bipartite :  two-parted. 

Bipinnate :  doubly  or  twice  pinnate ; 
164,  fig.  282. 


Bipinnately :  twice  pinnately,  161. 

Bipinndtijid:  doubly  or  twice  pinnati- 
fid;  161,fig.  280- 

Bipinndtisect :  twice-pinnately  divided, 
161. 

Biplicate :  twice  folded,  or  having  two 
folds. 

Bipdrose :  opening  by  two  small  holes 
or  pores,  fig.  474. 

Biradiate  :  consisting  of  two  rays. 

Birdlime,  469. 

Birimose :  opening  by  two  slits,  as  do 
most  anthers,  fig.  473. 

Bise'ptate:  having  two  partitions. 

Bise'rial,  or  bise'riate :  occupying  two 
rows,  one  within  or  above  the  other. 

Biserrate :  doubly  serrate,  i.  e.  the  teeth 
themselves  serrate. 

Bisexual :  having  both  stamens  and  pis- 
tils, 261. 

Bisulcate :  having  two  furrows. 

Bite'rnate :  twice  ternate ;  i.  e.  divided 
into  three  parts,  and  these  again 
into  three  ;  164,  fig.  284. 

Blackberry,  416. 

Bladdery :  thin  and  inflated,  like  a  blad- 
der. 

Blade  of  a  leaf,  petal,  &c,  145,  276. 

Bloom,  56,  144. 

Blueberry,  439. 

Boat-shaped:  concave  within  and  con- 
vex (and  often  keeled)  without. 

Bohon-Upas,  475. 

Borraginacea?,  450. 

Bothre'nchyma ,  45,  46. 

Brdchiate :  with  opposite  branches,  the 
successive  pairs  spreading  at  right 
angles  with  each  other. 

Bract  (Latin,  bractea)  :  the  leaves  of  an 
inflorescence,  especially  the  leaf 
which  subtends  a  flower,  143,  211. 

Brdcteate :  subtended  by  a  bract. 

Brdcteolate :  subtended  by 

Bractlets,  brdc.teoles  (Latin,  bracteolos)  : 
bracts  of  a  second  order,  &c,  or 
bracts  on  the  pedicel  or  the  flower- 
stalk,  211. 

Branches,  and  brancMets,  97. 

Brazil-wood,  414. 

Bread-fruit,  475. 

Breathing-pores,  52,  150. 

Bristles:  stiff  short  hairs  (52),  or  hair- 
like bodies. 

Bristly  :  beset  with  stiff  bristles. 

Bromeliacea?,  492. 

Bryology :  same  as  Muscology. 

Buckwheat,  466. 

Bud :  a  stem  or  branch  in  an  undevel- 
oped state,  93. 

Budding,  100. 

Bud-scales,  95,  167. 

Buffalo-berry,  468. 


526 


GLOSSARY    AND    INDEX. 


Bulb:  a  permanent  bud  with  fleshy 
scales,  mostly  subterranean,  109. 

Bulbiferous :  producing  bulbs. 

Bulb'lets  :  little  bulbs  above  ground,  109. 

Bulbose,  or  bulbous :  bulb-like  in  shape. 

Bulbo-tuber :  same  as  a  corm. 

Bullate :  a  surface  appearing  as  if  blis- 
tered, puckered,  or  bladdery  (from 
bulla,  a  bubble). 

Burmanniacese,  490. 

Burseracere,  406. 

Bursiculate  :  provided  with  pouch-like 
appendages  (bursiculte). 

Butomacere,  487. 

Butterfly-shaped  corolla,  253,  277. 

Butternut,  476. 

Byssaceous :  composed  of  fine  entangled 
threads  (byssus,  or  fine  flax). 

Byttneriaceas,  398. 

Cabombacea?,  386. 

Cactacete,  421. 

Caducous:  falling  off  at  the  time  of 
expansion,  as  the  calyx  of  the 
Poppy,  279. 

Csesalpinea;,  413. 

Ccesious :  lavender-colored. 

Ccespitose,  or  cespitose :  growing  in  tufts 
or  turfs. 

Cajeput  oil,  418. 

Calabash,  447. 

Calabash-Nutmeg,  383. 

Calat/ridium :  a  name  for  the  head  of 
Composite. 

Caldthiform  :  cup-shaped. 

Cdlcarate  :  bearing  a  spur  (calcar),  278  ; 
as  the  Violet,  fig.  396,  and  Lark- 
spur, fig.  398. 

Cdlceolate,  or  cdlciform,  slipper-shaped. 

Callitrichacese,  470. 

Callose :  furnished  with  callosities  (calli) 
or  hardened  or  protuberant  spots. 

Calvous :  bald. 

Calycanthaceae,  417. 

Cd/ycine  :  relating  to  the  calyx. 

Calyculate,  or  caliculate :  furnished  with 
an  outer  accessory  calyx  (calyculus), 
or  set  of  bractlets  resembling  a  ca- 
lyx, as  in  Dianthus. 

Cahjptra  :  the  hood  or  veil  of  the  spore- 
case  of  a  Moss,  503, 504  ;  or  a  body 
like  it,  389. 

Cahjptrate :  furnished  with  a  calyptra, 
or  something  like  it. 

Cahjptriform  :  shaped  like  a  calyptra  or 
candle-extinguisher,  as  the  calyx 
of  Eschscholtzia,  p.  389,  fig.  692. 

Calyx :  the  exterior  floral  envelope,  or 
leaves  of  the  flower,  222,  274. 

Cambium,  Cambium-layer,  122. 

Camelliaceaj,  400. 

Campanulacece,  438. 


Campdmdate  :  bell-shaped  ;  277,  fig. 
456. 

Camphor,  400,  467. 

Campylospe'rmous :  wlien  a  seed  or  seed- 
like fruit  is  rolled  up  so  as  to  form 
a  longitudinal  furrow  down  one 
side,  as  that  of  Sweet  Cicely. 

Campyldtropous  or  campyldtropal  ovule  or 
seed,  298,  299,  fig.  527. 

Canada  Balsam,  480. 

Canaliculate :  longitudinally  channelled. 

Cdncellate:  resembling  lattice- work. 

Candleberry,  477. 

Canescent:  whitened  or  hoary  with  fine 
and  close  pubescence. 

Cannabineas,  475. 

Cannacese,  490. 

Caoutchouc,  57,  458,  473,  475. 

Capers,  391. 

Capillary,  or  capilldceous  :  hair-like. 

Capitate :  headed  ;  having  a  globular 
apex  like  the  head  of  a  pin ;  or  col- 
lected into  a  head. 

Capitel/ate  :  diminutive  of  capitate. 

Capitidum  :  a  head  of  flowers,  as  of 
Clover,  Button-bush,  &c. ;  213,  fig. 
320. 

Capparidacea?,  391. 

Capre'olate :  furnished  with  tendrils. 

Caprifoliacese,  431. 

Capsular :  relating  to  a 

Capsule :  any  compound  dehiscent  fruit ; 
315,  fig.  582,  583. 

Cardamon,  490. 

Carina  :  a  keel ;  the  two  anterior  petals 
of  a  papilionaceous  flower  ;  254, 
fig.  392,  c. 

Cdrinate:  keeled  ;  furnished  with  a  pro- 
jecting longitudinal  ridge  along  the 
under  side. 

Cariopsis,  or  carydpsis :  a  grain,  314. 

Cameous :  flesh-colored. 

Carnose :  fleshy  in  texture. 

Carpel  (carpel lum  or  carpidium) :  a  sim- 
ple pistil,  or  one  of  the  elements  of 
a  compound  one,  290. 

Cdrpellary  :  pertaining  to  a  carpel. 

Carpolocjy :  the  department  of  Botany 
that  relates  to  fruits. 

Carpophore :  the  stalk  of  a  pistil,  267. 

Carrot,  426. 

Cartilaginous  :  tough,  like  cartilage. 

Cdruncle :  an  excrescence  at  the  hilum 
of  certain  seeds,  322. 

Carunculate :  furnished  with  a  caruncle. 

Caryophyllacea?,  395. 

Caryophyllaceous  (corolla)  :  pink-like, 
276. 

Carydpsis  :  a  grain,  314. 

Caseine,  198. 

Cashew,  406. 

Cassava,  472. 


GLOSSARY    AND    INDEX. 


527 


Cassia-bark,  467. 

Castor-oil,  472. 

Castrate  (stamen)  :  with  no  anther  or 
one  containing  no  pollen. 

Catapetalous :  where  the  petals  are  unit- 
ed with  each  other  at  the  base  and 
with  the  base  of  the  stamens,  as  in 
the  Mallow  family. 

Catechu,  414. 

Cate'nulate :  composed  of  parts  united 
end  to  end,  like  the  links  of  a  chain. 

Catkin:  see  Anient,  213. 

Caudate  :  tailed  or  tail-pointed. 

Caudex,  101. 

Caudicle  :  a  little  stalk,  like  that  of  the 
pollen-mass  of  Orchis,  &c.,  fig.  1235 

Caulescent :  obviously  having  a  stem. 

Caulicle :  a  little  stem,  or  a  rudimentary 
stem  ;  the  radicle,  71. 

Cauline,  or  caulinar:  relating  to  a 

Caulis :  the  main  stem,  91. 

Cayenne  pepper,  456. 

Cedrelacece,  401. 

Cedron,  405. 

Celastracese,  408. 

Cell :  a  cavity  of  an  anther,  ovary,  &c., 
281,  291.  In  vegetable  anatomy, 
one  of  the  vesicles,  or  elements  of 
which  a  plant  is  composed,  23. 

Cell-formation,  27. 

Cell-growth,  30. 

Cell-multiplication,  28. 

Cellular  bark,  or  envelope,  121. 

Cellular  Plants,  68. 

Cellular  tissue,  or  structure,  23. 

Cellule:  same  as  Cell  (in  veg.  anatomy). 

Cellulose,  27,  192. 

Celtidea?,  474. 

Centrifugal  inflorescence,  218. 
"  radicle,  326. 

Centripetal  inflorescence,  212. 
"         radicle,  326. 

Ceratophyllaceae,  470. 

Cereal :  belonging  to  corn  or  corn- 
plants  ;  these  having  been  called 
the  gift  of  Ceres. 

Cernuous :  nodding. 

Chaff:  the  scales  or  bracts  on  the  re- 
ceptacle which  subtend  each  a  flow- 
er in  the  heads  of  many  Composite, 
as  the  Sunflower;  also  the  glumes, 
&c.  of  Grasses  ;  215,  435. 

Chaffy :  provided  with,  or  of  the  texture 
of  chaff". 

Chaldza :  the  part  of  the  ovule  where 
the  coats,  nucleus,  &c.  are  all  unit- 
ed;   298,  fig.  521,  d,  526,  c. 

Channelled:  see  Canaliculate. 

Characeai,  510. 

Characters :  the  essential  marks  distin- 
guishing one  species,  genus,  &c. 
from  those  most  resembling  it,  362. 


Chartaceous :  of  the  texture  of  paper  or 
parchment. 

Chcckerberry,  441. 

Chenopodiacea;,  464. 

Cherry,  417. 

Chestnut,  477. 

Chldrophyll :  leaf-green,  58. 

Chlorosis :  a  loss  of  color  ;  a  reversion 
of  the  petals,  &c.  of  a  blossom  to 
green  leaves. 

Chlorospermeae,  509. 

Chocolate,  398. 

Chdrisis :  the  division  of  one  organ  into 
two  or  more,  243. 

Chromule:  the  coloring  matter  of  plants, 
especially  of  petals,  &c. 

Chrysobalanacece,  415. 

Cicatrix :  a  scar  left  by  the  fall  of  a  leaf 
or  other  organ. 

Cilia  (sing,  cilium,  the  eyelash) :  hairs  or 
bristles  fringing  the  margin  of  any- 
thing ;  those  of  the  inner  peristome 
of  a  Moss,  502. 

Ciliate :  the  margin  fringed  with  hairs. 

Cinchona,  432. 

Cinchoneae,  432. 

Cinenchyina,  49. 

Cinereous,  cineraceous :  ash-gray. 

Cinnamon,  467. 

Circinate:  involute  from  the  top;  144, 
fig.  219. 

Circulation  in  cells,  31,  178. 

Circumcissile,  or  circumscissile :  opening 
or  divided  by  a  transverse  circular 
line;  317,  fig.  588. 

Circumscription  :  the  general  outline. 

Cirrhose,  cirrhiferous :  tendril-bearing, 
or  with  organs  serving  as  a 

Cirrhus :  a  tendril. 

Cistaceas,  393. 

Cistdma :  a  kind  of  sac  lining  the  cham- 
ber under  a  stomate  in  certain 
plants. 

Classes,  360. 

Classification,  352. 

Clathrate :  latticed. 

Clavate, claviform :  club-shaped;  narrow 
below  and  thickened  towards  the 
summit. 

Claviculate :  with  tendrils,  or  leafstalks 
acting  as  such  (clavicular). 

Claiv:  the  narrowed  base  of  a  petal, 
&c,  276. 

Cleft :  cut  to  about  the  middle,  and  with 
narrow  or  acute  sinuses  ;  159,  fig. 
261,  265. 

Climbing :  rising  by  laying  hold  of  oth- 
er objects  in  any  way,  102. 

Clindnthium :  the  receptacle  of  the  flow- 
ers in  Composite. 

Cloves,  418. 

Club-shaped:  see  Clavate. 


528 


GLOSSARY   AND    INDEX. 


Clusiaceie,  400. 

Clustered :  collected  into  a  bunch. 

Clypeate :  buckler-shaped. 

Coacervate :  heaped  together. 

Coddunate :  cohering ;  united  at  the  base 
or  farther. 

Coalescence,  249. 

Coalescent :  growing  together. 

Coarctute :  crowded  together. 

Coated :  composed  of  layers ;  or  fur- 
nished with  a  rind. 

Cobwehbed,  or  cobwebby :  bearing  long 
hairs, like  cobweb  or  gossamer. 

Cocculus  Indicus,  384. 

Coccus  (pi.  cocci)  :  anciently  a  berry; 
now  used  for  the  closed  carpels  into 
which  many  fruits  split  (316),  as 
those  of  Euphorbia,  fig.  1143, 1 145, 
and  Verbena,  fig.  985. 

Cochledriform:  shaped  like  a  spoon  (coch- 
lear). 

Cocldeate :  like  a  snail-shell  (cochlea). 

Cocoa-plum,  415. 

Cielospe'rmous :  i.  e.  hollow-seeded  ;  the 
top  and  bottom  incurved,  as  in  Co- 
riander-seed. 

Coffee,  433. 

Coherent :  united  together. 

Cohesion  of  parts,  250,  &c. 

Coleorhiza  (root-sheath)  :  the  sheath  or 
covering  (belonging  to  the  cotyle- 
don or  plumule)  through  which  the 
radicle  of  most  Endogens  bursts  in 
germination. 

Collar,  collum :  the  neck  or  line  of  junc- 
tion between  the  primary  stem  and 
root. 

Collective  fruits,  318. 

Coloeynth,  423. 

Colored:  of  some  other  color  than  green. 

Columbo-root,  384,  457. 

Columella :  the  axis,  or  central  column, 
of  a  pod  or  spore-case. 

Column :  the  united  filaments  of  mon- 
adelphous  stamens,  or  the  united 
filaments  and  style  in  gynandrous 
flowers;  281,  fig.  468. 

Columnar :  pillar-shaped. 

Coma :  a  tuft  of  any  sort,  especially  a 
tuft  of  hairs  on  a  seed,  321,  fig. 
602  ;  the  whole  head  of  a  tree,  &c. 

Comate,  or  comose :  bearing  a  coma. 

Combrctacca?,  419. 

Commelynacea;,  or  Commelinaceae,  496. 

Commissure :  the  line  of  junction  of  two 
carpels ;  used  mostly  in  Umbel- 
liferas,  426. 

Common:  used  as  "general,"  opposed 
to  partial. 

Cdmplanate :  flattened. 

Complete  flower :  having  all  the  kinds  of 
organs,  222,  238. 


Complicate :  folded  upon  itself. 

Compositai,  435. 

Compound  flower,  215,  fig.  323-325,  and 
435,  fig.  887,  &c. 

Compound  leaf:  one  composed  of  two  or 
more  blades,  1 63. 

Compound  pistil,  290. 

Compound  spike,  raceme,  umbel,  &c,  216. 

Compressed :  flattened  on  two  opposite 
sides. 

Concentric  layers  of  wood,  112,  123. 

Conchiform :  shell-shaped. 

Concolored :  all  of  one  color. 

Conduplicate ;  folded  together  length- 
wise, 144,  165. 

Cone:  see  Strobile,  319. 

Conferruminate :  stuck  together  by  their 
adjacent  faces,  as  the  cotyledons  of 
Ilorsechestnut,  327. 

Confcrted:  crowded. 

Confluent :  running  together,  or  blended 
into  one. 

Conformed :  similar  to ;  or  closely  fitted 
to,  as  the  skin  to  the  kernel  of  a 
seed. 

Congested :  crowded  together. 

Conglobate:  clustered  into  a  ball. 

Conglomerate :  thickly  clustered. 

Coniferas,  479. 

Coniferous:  cone-bearing. 

Conjugate  :  coupled;  in  single  pairs. 

Conjugation,  332. 

Connate:  united  or  grown  together  from 
the  earliest  state,  251. 

Connate-perfoliate,  166,  fig.  294. 

Connective,  connectivum  :  the  part  of  the 
anther  connecting  its  two  cells  or 
lobes,  281,  282. 

Connivent :  converging. 

Conoidal:  approaching  a  conical  form. 

Consolidated:  when  unlike  parts  are 
grown  together. 

Consolidation,  250. 

Continuous :  not  interrupted. 

Contorted:  twisted,  272. 

Contortuplicate :  twisted  and  folded. 

Contracted :  either  narrowed  or  short- 
ened. 

Contrary  :  opposite  in  direction  to  some- 
thing it  is  compared  with,  as  the 
pod  of  Shepherd's  Purse  flattened 
contrary  to  the  partition. 

Convolute  (rolled  up)  or  cdnvolutive  aesti- 
vation, 272. 

Convolute  vernation :  rolled  up  length- 
wise in  the  bud,  144. 

Convolvulaeeze,  454. 

Copaiva,  414. 

Copal,  414. 

Copalche-bark,  434. 

Cordate :  heart-shaped ;  shaped  like  a 
heart  as  painted  upon  cards,  the 


GLOSSARY    AND    INDEX. 


529 


sinus,  or  notched  end,  being  at  the 
base ;  fig.  244. 

Cordiaceae,  451. 

Coriaceous :  of  a  leathery  consistence. 

Cork,  477. 

Corky :  of  the  texture  of  cork. 

Corky  envelope  or  layer  of  the  bark,  121, 
127. 

Conn  (cormus)  :  a  solid  bulb,  108. 

Cormophytes :  plants  having  an  axis 
(root  and  stem),  in  contradistinc- 
tion to  Thallophytes,  371 

Cornacese,  428. 

Corneous:  of  the  consistence  of  horn. 

Corniculate:  furnished  with  a  small 
horn. 

Cornine,  428. 

Cormtte:  furnished  with  a  horn  (eormi). 

Corolla  :  the  inner  of  the  two  floral  en- 
velopes, 222,  275. 

Corol/dceous,  cdrolline :  like  a  corolla  in 
appearance  or  texture,  or  belong- 
ing to  the  corolla. 

Cortina  :  a  crown,  such  as  the  append- 
age at  the  top  of  the  claw  of  the 
petals  of  Silene  ;  246,  fig.  378. 

Coronate :  bearing  a  crown. 

Cortex :  the  bark  or  rind. 

Cortical:  pertaining  to  the  bark. 

Corticate :  furnished  with  a  distinct  rind. 

Corymb :  a  convex  or  flat-topped  flower- 
cluster,  211. 

Ctirymbose:  disposed  in,  or  resembling, 
corymbs. 

Costa  :  a  rib,  or  midrib. 

Costate :  ribbed,  or  with  a  midrib. 

Cotton,  44,  398. 

Cotyle'dons :  the  first  leaves  of  the  em- 
bryo;  seed-leaves,  71,  324. 

Cotyliform :  dish-shaped. 

Coumarin,  414. 

Cowitch,  415. 

Cranberry,  439. 

Crassulaeeas,  423. 

Crate'riform :  goblet-shaped. 

Creeping :  running  on  or  beneath  the 
ground  and  rooting,  102. 

Cremocurp  :  the  fruit  of  Umbelliferoe, 
425. 

Crenate,  or  crenellcd:  the  margin  fur- 
nished with  even  and  rounded 
notches  or  scallops  ;  159,  fig.  256. 

Cre'nulate :  diminutive  of  Crenate. 

Crescentieae,  447. 

Crested:  see  Cristate. 

Cribrose :  pierced  with  holes  like  a 
sieve. 

Crinite :  bearded  with  long  hairs. 

Crispate :  curled. 

Cristate :  crested  ;  bearing  any  elevated 
appendage  on  its  surface. 

Cross-breeds :  individuals  originated  by 

45 


fertilizing  one  variety  or  species  bv 
another,  356,  357. 

Crowberry,  474. 

Crown  (246,  279,  fig.  378)  :  see  Corona. 

Crowned:  see  Coronate. 

Crowning :  borne  on  the  apex  of  any 
organ. 

Cruciate,  or  cruciform  :  cross-shaped, 
277,  as  the  corolla  of  the  Mustard 
family,  fig.  405. 

Cruciferse,  389. 

Crude  sap,  53,  190. 

Crustaceous :  crusty  in  texture,  hard 
and  brittle. 

Cryptogamia,  513. 

Cryptogamous  or  cryptogenic  :  relat- 
ing to 

Cryptogamous  Plants,  69,  330,  499. 

Crystals,  59. 

Cucullate,  or  cuculliform  :  hooded  or 
hood-shaped  ;  rolled  up  like  a  cor- 
net of  paper,  503. 

Cucumber,  423. 

Cucurbitacese,  423. 

Culm:  a  straw,  or  straw-like  stem,  101. 

Cultrate:  shaped  like  a  broad  knife- 
blade. 

Ciineale,  or  cuneiform  :  wedge-shaped  ; 
broad  above,  and  narrowed  to  the 
base,  with  straight  sides  ;  fig.  235. 

Cunoniacea?,  or  Cuuonieaj,  525. 

Cupressinese,  480. 

Cup-shaped,  cupuliform :  hemispherical, 
and  hollow  above. 

Cupulate  :  furnished  with  a 

Cupule,  or  cupula  :  the  acorn-eup,  314. 

Cupulifera?,  476. 

Curled:  irregularly  folded  and  crimped. 

Currant,  421. 

Curvinerved,  158,  fig.  236. 

Curvi serial :  in  curved  ranks,  141. 

Cuscutea?,  or  Cuscutinea?,  455. 

Cushion  :  the  swollen  base  of  a  leaf- 
stalk, or  the  enlargement  below  the 
insertion  of  many  leaves. 

Cuspidate :  tipped  with  a  cusp,  or  sharp 
and  rigid  point ;  162,  fig.  275. 

Custard-Apple,  382. 

Cut :  see  Incised,  or  Dissected. 

Cuticle :  the  outer  skin  or  pellicle  of  the 
epidermis,  149. 

Cydthiform  :  cup-shaped. 

Cycadacese,  481. 

Cycle :  one  complete  turn  of  a  spire ;  a 
circle. 

Cyclical :  coiled  into  a  full  circle. 

Cyc/tisis  :  circulation  in  cells,  31. 

Cyl indraceous :  approaching  to  the 

Cylindrical:  circular  in  transverse  out- 
line and  tapering  gradually,  if  at 
all,  as  in  most  stems. 

Cymbccform :  boat-shaped. 


530 


GLOSSARY    AND    INDEX. 


Cyme  (cyma)  :  a  cluster  of  centrifugal 
inflorescences,  218. 

Ci/mose :  bearing  cymes,  or  cyme-like. 

Cymule  (cymula)  :  a  cymelet,  or  little 
cyme,  218. 

Cynarrhodium :  such  a  fruit  as  that  of 
Hose  (fig.  429)  and  Calycanthus, 
fig.  815,819. 

CyperacesB,  496. 

Cypsela :  an  achenium  with  an  adher- 
ent calyx-tube,  as  in  Composite. 

Cystidium :  a  utricle. 

Cystoliih.es,  60. 

Cytoblast:  the  nucleus  of  a  vegetable 
cell. 

Dammcr  Pitch,  400. 

Deca-,  in  words  of  Greek  derivation  : 
ten  ;  as  in 

Decagy'nia,  515. 

Decdgynous :  with  ten  pistils  or  styles. 

Decdmerous :  the  parts  in  tens,  234. 

Decandria,  512. 

Decandrous :  with  ten  stamens,  280. 

Decape'talous  :  with  ten  petals,  276. 

Deciduous :  falling  off,  or  subject  to 
fall ;  as  petals  falling  after  blos- 
soming, 279,  and  leaves  before 
winter,  172. 

Declinate,  declined:  turned  to  one  side. 

Decompound:  several  times  compound- 
ed, 165. 

Decumbent :  reclined  on  the  ground,  the 
summit  rising,  102. 

Decurrent:  prolonged  below  the  inser- 
tion, as  the  leaves  of  the  Thistle, 
170. 

Decussate :  the  successive  pairs  crossing 
each  other  at  right  angles,  142. 

Deduplication  (dedoublement) ,  243. 

Definite :  of  a  fixed  number,  and  not 
above  twelve  or  twenty. 

Definite  growth,  100. 

Definite  inflorescence,  217. 

Deflexed :  bent  downwards. 

Dfldrate :  past  the  flowering  state. 

Defoliate :  having  cast  its  leaves. 

Dehiscent  fruits,  &c,  315  ;  opening  by 

Dehiscence :  splitting,  as  do  pods,3 11,316. 
"         of  anthers,  283. 

Deliquescent :  the  stem  dissolving  into 
branches,  99. 

Deltoid:  shaped  like  the  Greek  capital  A. 

Demersed:  growing  under  water. 

Dendroid,  dendritic :  tree-like. 

Dentate :  same  as  toothed  ;  159,  fig.  255. 

Denticulate  :  furnished  with  fine  teeth,  or 
denticulations. 

Denudate :  made  naked. 

Depauperate :  dwarfed  in  size. 

Depressed:  flattened  vertically  or  from 
above. 


Descending :    tending   gradually    down- 
wards. 
Descending  axis,  72,  79. 
Dcsmiduc,  or  Dcsmidiaccce,  510. 
Determinate  inflorescence,  217. 
Descriptive  Botany,  15. 
Development,  19. 
Dextrine,  54,  193. 
Dextrorse  :  towards  the  right. 
Di-,  in  Greek  compounds  ;  two. 
Diadelphia,  513. 

Diade'lphous :    stamens  united  by  their 
filaments  in  two  sets ;  280,  fig.  40 1. 
Diandria,  512. 

Didndrous :  with  two  stamens,  279. 
Diagnosis :  a  brief  essential  character. 
Dialype'talous  :  of  distinct  petals. 
Diapensiaccas,  454. 
Diaphanous :  transparent. 
Diatomacese,  510. 
Dicdrpellary  :  of  two  carpels. 
Dichlamydeous :    with  both   calyx   and 

corolla. 
Dichondrcae,  455. 

Dichdlomous :  forking  into  two  branches. 
Diclinous :  with  the  stamens  and  pistils 

in  separate  blossoms,  261. 
Dicdccous  :  separable  into  two  cocci. 
Dicotyledonous :  having  a  pair  of  cotyle- 
dons, 78,  326. 
Dicotyledons,  Dicotyledonous   Plants, 

114,326,370. 
Didymous :  twin. 
Didynamia,  512. 
Didynamous :    with  two  long  and  two 

shorter  stamens,  258,  281. 
Difformed:  of  unusual  shape. 
Diffuse:  widely  and  loosely  spreading. 
Digamous :  having  flowers  of  two  dif- 
ferent sexes. 
Digestion,  190. 

Digitate  (fingered) :  compound,  with  the 
parts   all   arising  from  the   same 
point  ;   163,  fig.  277. 
Digitately  tri-plurifoliolate,  164. 
Digynia,  515. 

Digynous :  with  two  pistils  or  styles,  287. 
Di'lieniaceas,  380. 

Dimerous :  the  parts  in  twos,  234,  239. 
Dimidiate:  halved,  or  appearing  as  if 
one  half  or  side  were  wanting,  283. 
Dimdrphous :  of  two  forms. 
Dicecia,  513. 

Diacious  :  with  stamens  and  pistils  in 
separate     blossoms    on     different 
individuals,  262. 
Dioscoreaceas,  492. 
Diosmeos,  407. 

Dipetalous  :  of  two  petals,  276. 
Diphyllous :  two-leaved,  275. 
Diploste'monous :     stamens    double    the 
petals  or  sepals  in  number. 


GLOSSARY   AND    INDEX. 


531 


Dipsaceae,  435. 

Dipterocarpeas,  400. 

Dipterous :  two-winged. 

Disciform:  disk-shape;  flat  and  circu- 
lar, like  a  disk  or  quoit. 

Discoidal,  discoid :  like  a  disk ;  or  be- 
longing to  the  disk ;  destitute  of 
rays,  436. 

Dise'palous  •  of  two  sepals. 

Disk,  or  disc:  a  fleshy  expansion  of  the 
receptacle  of  a  flower,  267  :  the 
central  part  of  a  head  of  flowers, 
as  opposed  to  the  border,  436  ;  the 
face  of  any  flat  body,  as  opposed 
to  the  margins. 

Disk-bearing  woody  tissue,  43. 

Disk-flowers,  436. 

Dissected :  cut  into  pieces,  or  nearly  so. 

Disse'piment :  the  partition  of  a  pod,  291. 

Dissident :  bursting  in  pieces. 

Distichous:  in  two  vertical  ranks,  134. 

Distinct :  when  parts  of  the  same  name 
are  unconnected,  251. 

Divaricate :  straddling  widely. 

Divergent :  separating,  their  summits 
inclining  from  each  other. 

Divided:  cut  into  distinct  portions; 
160,  fig.  263,  267. 

Dodeca- :  in  Greek  derivatives  ;  twelve. 

Dodecagynia,  515. 

Dodecdgynous :  with  twelve  pistils  or 
styles. 

Dodecandria,  512. 

Dodecdndrous :  with  twelve  (or  from 
twelve  to  nineteen)  stamens,  280. 

Doldbriform :  axe-shaped. 

Dorsal :  belonging  to  the  back  (dorsum). 

Dorsal  suture,  289. 

Dotted  ducts,  38. 

Dotted  leaves,  &c. :  marked  with  small 
spots,  either  colored,  or  transparent 
and  appearing  like  punctures. 

Double  flowers  :  monstrous  blossoms, 
with  the  petals  unduly  multiplied, 
222   229. 

Douhhj  compound,  164. 

Downy :  clothed  with  soft  pubescence. 

Dragon's  blood,  414,  493. 

Droseraeea?,  394. 

Drupaceous :  like  or  pertaining  to  a 

Drupe:  a  stone-fruit,  312. 

Drupelet:  a  diminutive  drupe,  313. 

Dryadese,  418. 

Ducts,  45. 

Dumose:  bushy. 

Duplicate  :  doubled  or  folded. 

Duramen:  heart-wood,  126. 

Dwarf:  comparatively  low  in  stature. 

E-,  or  Ex-,  as  a  prefix,  means  destitute 
of ;  as,  ecostate,  riblcss  ;  exalbumi- 
nous,  without  albumen,  &c. 


Eared:  see  Auriculate. 

Earthy  constituents  of  plants,  179,  186. 

Ebenaceae,  442. 

Ebe'neous :  black  like  ebony. 

Ebony,  442. 

Ebrdcteale :  destitute  of  bracts. 

Ebrdcteolate :  destitute  of  bractlets. 

Eburncous  :  white  like  ivory. 

Ecldnate:  beset  with  prickles  (like  a 
hedgehog). 

Echimdate :  rough  with  small  prickles. 

Ede'ntate :  toothless. 

Ejffete:  past  the  perfect  or  productive 
state. 

Effuse :  very  loosely  spreading. 

Efjlandulose :  destitute  of  glands. 

Elaborated  sap,  53. 

Elasagnaceas,  467. 

Elaters,  40,  505. 

Elatinaceee,  395. 

Elementary  constituents  of  plants,  179. 

Elementary  structure  of  plants,  17. 

Ellipsoidal :  approaching  the  form  of 

Elliptical:  oval  or  oblong,  and  witli 
both  ends  similar  and  regularly 
rounded. 

Eman/inate:  notched  at  the  end  ;  162, 
fig.  273. 

Embracing :  surrounding,  as  by  abroad 
.      attachment. 

Embryo:  the  rudimentary  plantlet  in  a 
seed,  71,323. 

Emliryo-sac,  304. 

Embryogenij :  the  formation  of  the  em- 
bryo, 304. 

Embryonal  vesicle,  306. 

Emersed :  raised  out  of  water. 

Emetine,  433. 

Enantiobldstous  :  with  the  embryo  at  the 
end  of  the  (orthotropous)  seed  dia- 
metrically opposite  the  hilum,  as  in 
Tradescantia. 

Endecagynia,  515. 

Endecdgynous :  with  eleven  pistils  or 
,      styles. 

Endocarp :  the  inner  laver  of  a  pericarp, 
,       310,  312. 

Endochrome :  the  coloring  matter  of 
,       Alga;. 

Endopen,  Endocenae,  Endogenous 
Plants,  113,  370,  482. 

Endogenous  structure,  113,  114. 

Endophldum  :  inner  bark,  120. 

Endopleura :  the  innermost  seed-coat, 
321. 

Endorhizse  :  a  synonyme  for  Endogens. 

Endorldzal :  said  of  an  embryo  which 
has  the  radicle  sheathed  by  the 
cotyledon  or  plumule  wrapped 
around  it. 

Endosmdse,  or  Endosmdsis,  33. 

E'ndosperm :  the  albumen  of  the  seed, 


532 


GLOSSARY   AND    INDEX. 


especially  when  this  is  formed  in  the 
,      embryo-sac  of  the  ovule,  322,  323. 
Endostome :     the    orifice   of  the   inner 

coat  of  the  ovule,  298. 
Endothelium:   the  inner  lining  of  the 

cells  of  an  anther. 
Enerved :  nerveless. 
Ennea- :  nine ;  as  in 
Enneagynia,  515. 

Enneugynous :  with  nine  pistils  or  styles. 
Enneandria,  512. 
Enncdndrous :  with  nine  stamens. 
Enneape'talous :  nine-petalled,  276. 
Enddal:  without  a  node. 
Ensate :  same  as 
Ensiform  :  sword-shaped. 
Entire  :  the   margin  whole  and  even, 

not  toothed  or  cut,  158,  275. 
Entophytcs  :  plants  parasitic  within  oth- 
er plants. 
Epacridc.T,  440. 
Ephemeral :  lasting  but  a  day. 
Epi-,  in  Greek  compounds :  upon. 
Epicdlyx :  an  involuccl  resembling  an 

exterior  calyx,  as  in  Mallow. 
Epical p:  the  outermost  layer  of  a  peri- 
carp, 310. 
Epichilium :  the  upper  part  of  the  lip  of 

an  Orchid,  when  different  from  the 

lower. 
Epicdrolline  :  upon  the  corolla. 
Epidermal :  relating  to  the 
Epidermis:    the   skin  of  a  plant;   51, 

122,  148. 
Epigeeous :  growing  on  or  close  to  the 

ground. 
Epigynous :  upon  the  ovary,  252,  268, 

281. 
Epipetalous :  upon  the  corolla,  281. 
Epiphldum  :  outer  or  corky  bark,  121. 
Epipkyllous  :  upon  a  leaf. 
Epiphytal,  or  epiphytic  :  relating  to 
E'piphytes,    plants  growing    affixed  to 

another  plant,  but  not  nourished 

by  it,  87. 
Epipterous  :  winged  at  the  top. 
Epispcrm  :  the  outer  seed-coat,  320. 
Equal:  regular,  or  of  the  same  length 

or  number,  as  the  case  may  be. 
Equilateral:  equal- sided. 
Equisetacece,  499. 

E'quitant:  riding  straddle,  145,  165. 
Erianthous :  woolly-flowered. 
Ericaceae,  439. 
Ergot,  498. 
Eriocaulonacese,  496. 
Eriogoneai,  466. 
Erose:  eroded,  as  if  gnawed. 
Erostrate :  not  beaked. 
Escalloniere,  425. 
Essential  organs  of  the  flower,  222. 
Estivation :  see  ^Estivation. 


Etozrio :  a  name  for  such  a  fruit  as  a 
raspberry  and  blackberry. 

Euphorbiacea:,  471. 

Evalved,  or  evdlvular  :  valveless. 

Evergreen :  holding  the  leaves  over  win- 
ter or  longer,  172. 

Exalbuminous  :  without  albumen,  323. 

Excentric :  out  of  the  centre,  325  ;  one- 
sided. 

Excretions,  57,  178. 

Excurrent :  protruding  beyond  the  apex, 
as  when  the  midrib  of  a  leaf  pro- 
jects :  or  running  to  the  very  sum- 
mit, as  the  main  stem  of  a  Fir,  99. 

Exhalation,  175. 

E'xocarp :  the  outer  layer  of  a  pericarp, 
,       312. 

Exogcn,  Exogense,  Exogenous  Plants, 
113,  370. 

Exogenous  structure,  113,  116. 

Exorhiza} :  a  synonyme  of  Exogens  ; 
the  radicle  in  these  being 

Exorhizal:  not  enclosed  or  sheathed 
by  the  cotyledons  or  plumule. 

Exosmdse,  or  Exosmosis,  33. 

E'xostome :  the  orifice  of  the  outer  coat 
of  an  ovule,  298. 

Exostosis  :  an  indmated  protuberance. 

Exotheciitm  :  outer  coat  of  the  anther. 

E'xplanate :  outspread  or  broadly  flat- 
tened. 

Exserted,  exse'rt :  protruding  beyond,  as 
the  stamens  out  of  the  corolla  in 
fig.  450. 

Exstijndate :  destitute  of  stipules,  171. 

Exterior :  as  applied  to  the  parts  of  a 
blossom,  the  same  as  anterior. 

Extine :  the  outer  coat  of  a  pollen-grain, 
286. 

Extra-axillary  :  out  of  the  axil,  99, 
220. 

Extrorse :  turned  outwards,  282. 

Faries  :  the  general  aspect. 

Falcate,  falciform  :  scythe-shaped  ;  flat 
and  curved,  the  edges  parallel. 

Families,  359. 

Fan-shaped :  see  Flabelliform. 

Farina  :  starch,  54. 

Farinaceous  :  mealy;  containing  starch. 

Farinose :  covered  with  mealy  powder. 

Fdsciate :  banded ;  applied  also  to  mon- 
strous stems  which  grow  flat. 

Fasciation  :  the  singular  monstrous  ex- 
pansion of  stems,  &c.  as  in  the  gar- 
den Cock's-comb. 

Fascicle :  a  close  cyme  or  cluster  of 
flowers,  219;  a  bundle  of  leaves 
crowded  like  those  of  the  Larch, 
fig.  213. 

Fascicled :  growing  in  tufts  or  clusters, 
84,  142. 


GLOSSARY   AND    INDEX. 


533 


Fasciculate :  in  small  tufts. 
Fastigiate:  close,  parallel,  and  upright. 
Faux  (pi.  fauces)  :  the  gorge  or  throat. 
Fdveolate,  /arose :    with  deep  pits,  like 

honeycomb. 
Feather-veined:   having  veins  all   pro- 
ceeding from  a  midrib,  155. 
Feather)/ :  see  plumose. 
Ferula:    starch,  54. 
Female  flower :  see  Fertile  flower. 
Fene'strate:  pierced  with  one  or  more 

holes,  like  windows. 
Ferrugineous  or  ferruginous :  of  the  color 

of  iron-rust. 
Fertile:    capable    of    producing    fruit. 

Stamens  are  also  said  to  be  fertile 

when   their  anthers  contain  good 

pollen. 
Fertile    flower:     one     having    pistils, 

261. 
Fertilization,  300. 
Fibre,  41. 
Fibril :  a  delicate  fibre-like  body ;  the 

root-hairs,  81. 
Fibrilliform  tissue,  48. 
Fibrillose:   bearing  fibrils  :    diminutive 

of  fibrous. 
Fibrine,  198. 
Fibrous  or  fibrose :  composed  of  slender 

threads  or  fibres. 
Fibro-vascular  tissue  or  system,  50. 
Ficldle-shaped :  obovate  and  contracted 

on  each  side. 
Fig,  215,  475,  and  fig.  590-592. 
Filament :  the  stalk  of  an  anther,  223, 

281.     Or  any  slender  thread. 
Filamentous,  or  filamentose :   composed 

of  threads  or  filaments. 
Filices  (Ferns),  500. 
Filicology :   the  part  of  Botany  which 

treats  of  Ferns. 
Filiform :  shaped  like  a  thread ;  slender 

and  terete,  166. 
Filipe'ndulous :  hanging  from  a  thread, 

as  the  tuberous  roots  of  Spiraea  fili- 

pendula. 
Fimbriate :  fringed ;  bordered  by  slen- 
der processes  or  appendages. 
Fimbrillate  or  fimbrilliferous :     diminu- 
tive of  the  last. 
Fingered:  see  Digitate. 
Fissiparous  :    propagating   by    division 

into  two  portions. 
Fistular  or  Fistulose:  hollow   through 

its  length,  as  the  leaves  of  Onion. 
Fldbellate,  or  flabe'lliform  :  fan-shaped  ; 

broadly    wedge-shaped    with    the 

summit  rounded. 
Flacourtiaeeai,  392. 
Fldgellate:  bearing flagella,  i.  e.  runners, 

like  those  of  the  Strawberry. 
Flageiliform :  long,  taper,  and  supple, 

45  * 


like  the  thong  of  a  whip  ;  runner- 
like. 

Flavescent :  yellowish  or  pale  yellow. 

Flavous :  }-ellow. 

Flax,  402. 

Fleshy :  succulent,  or  of  the  consistence 
of  flesh,  84. 

Fle'xuose,  or  flexuous :  zigzag  ;  bent  alter- 
nately inwards  and  outwards. 

Floating :  growing  on  the  surface  of 
water. 

Floccose :  bearing  or  clothed  with  locks 
of  soft  hairs  or  wool. 

Flora  (the  goddess  of  flowers)  :  the  ag- 
gregate of  the  species  of  plants  of  a 
country  ;  or  a  work  systematically 
describing  them. 

Floral :  belonging  to  the  flower. 

Floral  envelopes :  flower-leaves,  222,  268 

Florescence:  same  as  anthesis. 

Floret :  a  small  flower,  or  a  separate 
blossom  of  a  so-called  compound 
flower. 

Florideai,  509. 

Floriferous :  flower-bearing. 

Fldsculous:  composed  of  or  bearing  flos- 
culi,  i.  e.  florets ;  or  composed  of 
tubular  flowers  only. 

Flower,  70,  221. 

Flower-bud,  209,  224. 

Flowering,  204. 

Flowering  Plants,  69,  369,  375. 

Flowerless  Plants,  69,  330,  499. 

Fluitant :  floating  on  water. 

Fluviatile :  belonging  to  flowing  water. 

Fly-traps,  168. 

Foliaceous:  leaf-like,  i.  e.  thin,  membra- 
naceous and  green;  or  bearing 
leaves. 

Foliar:  belonging  to  leaves  (folia). 

Foliation :  leafing  out. 

Foliate :  clothed  with  leaves  ;  or,  with  a 
numeral  prefix,  denoting  the  num- 
ber of  leaves  ;  as,  bifoliate,  two- 
leaved  :  trifoliate,  three-leaved,  &c. 

Fdliolate:  consisting  of  leaflets  (fo- 
liola)  ;  as,  bifoliate,  a  leaf  having 
two  leaflets,  or  trifoliolate,  having 
three  leaflets,  &c. 

Fdliose :  bearing  numerous  leaves. 

Follicle:  a  simple  pod  opening  down 
one  side  ;  315,  fig.  579. 

Follicular,  of  the  nature  of  a  follicle. 

Foramen  :  an  aperture  or  orifice,  298. 

Forami'nulose :  pierced  with  small  holes. 

Fdrcipate  :  forked  like  a  pair  of  pincers. 

Forked:  branching  into  two  or  more 
divisions. 

Fornicate :  arched  over,  bearing  a 

Fornix,  pi.  fdrnices :  little  arched  scales 
in  the'  throat  of  a  corolla,  as  in 
that  of  Hound's-tongue. 


534 


GLOSSARY   AND    INDKX. 


Fdveate :  pitted,  having  fovea  or  depres- 
sions of  the  surface. 

Fdveolate :  marked  with  little  pits  or  de- 
pressions (fove'olce). 

Fovilloz:  minute  particles  in  the  fluid 
contained  in  pollen,  286. 

Free :  separate ;  not  uuited  with  dis- 
similar parts,  250. 

Fringed :  see  Fimbriate. 

Frond:  the  foliage  or  Ferns  (500), 
Liverworts  (504),  &c.,  67. 

Frondescence  :  the  act  of  leafing. 

Frondose :  leafy,  or  more  commonly  it 
now  means  frond-like,  or  producing 
a  frond  instead  of  ordinary  foliage, 
504. 

Fructification :  fruiting,  or  the  fruit  and 
what  attends  it. 

Fructification,  organs  of:  the  stamens 
and  pistils. 

Fruit,  308. 

Fruit-dots,  of  Ferns,  501. 

Frumentaceous :  producing  starch,  or  re- 
lating to  corn  (frumentum). 

Fnistulose :  consisting  of  small  portions 
or  fragments. 

Frutescent :  becoming  shrubby. 

Fruticulose :  very  small  and  shrubby. 

Fruticose :  shrubby  ;  relating  to  a 

Frutex :  a  shrub. 

Fucaceae,  509. 

Fugacious :  falling  off  or  perishing  very 
early,  as  the  calyx  of  the  Poppy, 
and  the  corolla  of  Cistus  ;  172. 

Fulcrate :  belonging  to  or  furnished  with 
fulcra  (props),  i.  e.  with  append- 
ages such  as  tendrils,  prickles,  stip- 
ules, &c. 

Fidiginous,  or  fuliginose :  sooty ;  dark 
and  deep  Drown. 

Fulvous :  tawny  :  orange-yellow  mixed 
with  gray. 

Fumariacea%  389. 

Fundamental  organs,  70. 

Fungi,  507. 

Fungiform :  mushroom-shaped. 

Fungilliform :  diminutive  of  the  last. 

Fungose :  spongy  in  texture. 

Funiculus :  the  seed-stalk,  297,  321. 

Funnel-shaped,  funnel-form  :  sec  Infun- 
dibuliform,  277. 

Furcate :  forked,  the  forks  spreading. 

Furfuraceous :  scurfy. 

Furrowed:  see  Sulcate. 

Fuscous :  grayish-brown. 

FUsiform  :  spindle-shaped  ;  84,  fig.  138. 

Fustic,  475. 

Galbanum,  427. 

Gallmlus :  a  fleshy  and  closed  strobile 
imitating  a  berry,  as  a  Juniper- 
berry,  320. 


Galea:  a  helmet;  an  arched  sepal  or 
petal,  278,  fig.  458. 

Gdleate :  having,  or  shaped  like,  a  hel- 
met. 

Galingale,  490. 

Galls,  477. 

Gamboge,  400. 

Gdmoplii/llous :  composed  of  leaves 
united  by  their  edges,  275. 

Gamope'talous :  composed  of  united  pe- 
tals, 249,  275. 

Gamose'palous :  of  united  sepals,  249. 

Gelatinous  coils  in  cells,  40. 

Geminate :  in  pairs. 

Gemma  :  a  bud  or  growing  point. 

Gemmation  :  budding  growth,  31. 

Ge'mmule :  a  young  bud  ;  the  plumule. 

Genera  :  plural  of  genus. 

General :  the  opposite  of  partial ;  as  the 

General  involucre  of  a  compound  um- 
bel, &c,  216; 

Generic:  relating  to  the  genus. 

Geniculate:  bent  abruptly  like  a  knee. 

Gentianacese,  456. 

Gentianine  (Gentian),  457. 

Genus,  358. 

Geographical  Botany  :  the  study  of 
plants  in  respect  to  their  geograph- 
ical distribution. 

Geraniacea:,  403. 

Germ  :  the  eye  of  a  bud ;  or  any  grow- 
ing point ;  or  an  embryo,  323. 

Germen  :  an  old  name  for  the  ovary. 

Germinal  vesicle,  306. 

Germination  :  growth  of  the  embryo 
from  the  seed,  71,  328. 

Gerontoijoious :  belonging  to  the  Old 
World. 

Gesncriaceoe,  447 

Gibber:  an  enlargement,  or  gibbosity 
of  any  sort,  on  one  side  of  a  calyx, 
a  fruit,  &c. 

Gibberose  or  gibbous:  swollen  or  en- 
larged on  one  side. 

Gills  of  Fungi,  500. 

Ginger,  490. 

Ginseng,  428. 

Glabrous :  smooth,  i.  e.  destitute  of  hair- 
iness. 

Glabrate :  smoothed,  or  becoming  near- 
ly glabrous. 

Glddiate :  sword-shaped. 

Glands :  any  secreting  apparatus,  52. 
The  name  is  also  given  to  any  pro- 
jection or  appendage  the  nature 
and  function  of  which  is  not  obvi- 
ous, 264.  Glans  is  also  the  classi- 
cal name  of  an  acorn  and  chestnut. 

Glandular,  glanduliferous,  glandulose  : 
bearing  glands,  or  gland-like  in 
texture. 

Glandular  hairs,  52. 


GLOSSARY    AND    INDEX. 


535 


Glandular  icoody  tissue,  43. 

Glarcose:  growing  in  gravelly  places. 

Glaucescent :  verging  upon  or  slightly 

Glaucous:  covered  with  a  whitish  bloom, 
which  rubs  off,  as  the  surface  of  a 
cabbage-leaf  or  a  plum,  or  so 
whitened  as  to  appear  to  have  a 
bloom,  56. 

Globose  :  spherical  or  nearly  so. 

Globular :  nearly  globose  or  spheri- 
cal. 

Glochideou?,  or  glochidiate  :  barbed ; 
hooked  back  at  the  point,  like  the 
barb  of  a  fish-hook,  or  with  two  or 
more  such  barbs  at  the  point. 

Glomerate :  clustered  into  a 

Gldmerule :  a  capitate  cyme,  i.  e.  a  cyme 
condensed  into  a  head,  219. 

Glossology:  the  department  of  Botany 
which  explains  the  technical  terms 
of  the  science,  15. 

Gluniaceous:  bearing,  or  resembling 
glumes. 

Glume :  one  of  the  husks  or  chaff  of 
Grasses,  &c.,  497. 

Glumelle :  an  inner  glume  or  palea. 

Gluten,  197. 

Glutine,  198. 

Go'nophore :  a  stalk  elevating  both  sta- 
mens and  pistil,  267. 

Gooseberry,  421. 

Gossijpine:  cottony. 

Gourd  (a  pepo),  423. 

Grafting,  100. 

Grain,  314. 

Graminese,  497. 

Granadilla,  422. 

Granular :  composed  of  grains  or  gran- 
ules. 

Granulate:  composed  of  little  kernels 
or  coarse  grains. 

Granules:  anv  minute  particles. 

Grape,  408. 

Green  layer  of  the  bark,  121. 

Grossulacea?,  420. 

Grumous,  or  grumose:  consisting  of 
clustered  grains. 

Guaiacum,  405. 

Guava,  418. 

Gum  Animi,  400.  Gum  Arabic,  414. 
Gum  Elemi,  407.  Gum  Traga- 
canth  and  Senegal,  414. 

Gutta-percha,  57. 

Guttate :  sprinkled  with  colored  dots  or 
small  spots. 

Guttiferae,  400. 

Gymnocdrpous :  naked-fruited. 

Gymnospermia,  315. 

Gymiwspermous :  naked-seeded,  296. 

Gymnosperms,  or  Gvmnospermous 
Plants,  297,  371,  479. 

Gyiuicium  :  the  pistils  of  a  flower,  223. 


Gynandria,  513 

Gyndndrous :  stamens  borne  on  the  pis- 
til, especially  on  the  stvle;  253, 
281,  fig.  468. 

Gynobase :  the  base  of  a  style,  or  sum- 
mit of  a  receptacle,  on  or  around 
which  two  or  more  carpels  are  in- 
serted, as  in  Rue,  Sage,  Geranium, 
&c,  267. 

Gynophore :  the  stalk  of  a  pistil,  267. 

Gyrate  or  gyrose :  bent  round,  or  bent 
back  and  forth. 

Habit  (Habitus):  the  general  aspect  of 

a  plant. 
Habitat:  the  habitation,  or  situation  in 

which  a  plant  is  naturally  found. 
Hackbcrry,  474. 
Haematine,  414. 
Hannodoracece,  492. 
Hairs,  52. 
Hairy :    clothed  or  beset   with   hairs, 

which  are  separately  distinguish- 
able. 
Halberd-shaped,  or  Halberd-headed:   see 

Hastate. 
Halorageas,  420. 
Halved:  sec  Dimidiate  ;  appearing  as  if 

one  half  was  absent. 
Hamamelacess,  425. 
Hamate,  ovhamose:  hooked. 
Hdmulose:  diminutive  of  hamate. 
Hastate  :   halberd-beaded  ;    shaped  like 

a  halberd,  viz.  with  a  spreading 

lobe  at  the  base  on  each  side ;  157, 

fig.  250. 
Hazel-nut,  476. 
Head:      see     Capitulum ;     213,     fig. 

320,  &c. 
Headed:  same  as  capitate. 
Heart-shaped:  see  Cordate. 
Heart-wood,  35,  124,  126.  * 

Hebetate :  blunted,  having  a  soft  obtuse 

point. 
Helicoid :    coiled  into  a  helix  or  snail- 
shell,  or  tending  to  be  rolled  up  ; 

as  in  Fig.  332. 
Helmet:  see  Galea,  278. 
Helobious :  living  in  marshes. 
Heivolous :    grayish-yellow  mixed  with 

some  red. 
Hemi-  in  Greek  derivatives  :  halved  or 

half;  as 
Hemi-andtropous :  half-anatropous. 
He'micarp  :  a  half-fruit  of  Umbelliferae  ; 

same  as  mericarp. 
Hemitropal,  or  hemitropous :  nearly  the 

same  as  amphitropous. 
Hemp,  475. 
Hepatica;,  503. 
Hepta  :  the  Greek  numeral  seven,  used 

in  the  following  compounds. 


536 


GLOSSARY   AND   INDEX. 


Heptagynia,  515. 

Heptdgynous :   having   seven  pistils   or 

styles. 
Heptdmerous :  the  parts  in  sevens. 
Heptandria,  512. 

Heptdndrous :  with  seven  stamens,  280. 
Heptape'talous :  of  seven  petals,  276. 
Herb,  101. 

Herbaceous :  not  woody  ;  of  a  soft  text- 
ure like  an  herb,  101,  102. 
Herbarium  :  the  botanist's  collection  of 

dried  specimens  of  plants,  518. 
Hermaphrodite:  bisexual,  261. 
Hesperidium :  a  firm-rinded  berry  like 

an  orange,  311. 
Hetero-,  in  Greek  derivatives  :  unlike ;  as 
Heierocdrpous:  having  two  kinds  of  fruit. 
Heteroceplialous :   bearing  two  kinds  of 

heads  ;  as  in  Baccharis. 
Heterodrdmous,  140. 
Heterdgamous :    bearing    two    sorts    of 

flowers,  436. 
Heterogeneous  :  of  two  or  more  kinds. 
Heterdtropous,  or  heterutropal,  ovule  or 

seed  :  same  as  amphitropous,  300. 
Hexa-,  in  Greek  derivatives ;  six. 
Hexagynia,  515. 
Hexdgynous:     having     six     pistils     or 

styles. 
Hexdmerous  :  the  parts  in  sixes,  234. 
Hexandria,  512. 

Hexdndrons  :  with  six  stamens,  279. 
Hexape'talous :  six-pctalled,  276. 
HexaplnjUous :  six-leaved,  275. 
Hexdpterous :  six-winged. 
Hexase'palous :  with  six  sepals,  272. 
Hexasle'monous :  having  six  stamens. 
Hickory-nut,  476. 
Hidden-veined :  where  the  veins  are  not 

visible,  as  those  of  the  leaves  of 

Pinks  and  Houseleeks. 
Hilar :  relating  to  the  hilum. 
Hilum:  the  scar,  or  point  of  attachment 

of  the  seed,  297,  321. 
Hippocastanaceaj,    or  Hippocastaneas, 

410. 
Hippocre'piform :  horseshoe-shaped. 
Hirsute:  clothed  with  coarse  hairs. 
Hispid :  beset  with  stiff  bristly  hairs. 
Hoary :   grayish-white  from  a  fine  pu- 
bescence. 
Homocarpous :  bearing  fruits  all  of  one 

kind. 
Homodrdmous,  or  homodromal,  140. 
Ilomdgamous :  when  all  the  flowers  of  a 

head,  &c.  are  alike,  436. 
Homogeneous :  all  of  the  same  nature  or 

structure. 
Homologous :  of  the  same  name ;    said 

of  parts  which  are    of  the   same 

morphological  nature ;  e.  g.  bracts, 

sepals,  petals,  stamens,  and  sim- 


ple pistils  are  homologous  with 
leaves;  225,  231.     See  Analogous. 

Homologue  :  an  homologous  part. 

Homdmallous  (leaves,  &c.) :  originating 
all  round  an  organ,  but  directed  or 
curved  round  to  one  side  of  it. 

Homomdrphous :  of  one  form. 

Homotropous,  or  homotropal  (embryo)  : 
curved  in  the  same  way  as  the  seed, 
as  in  the  Cliickweed,  fig.  621. 

Hops,  475. 

Horny:  see  Corneous. 

Horizontal  system,  50,  112. 

Hortus  Siccus:  same  as  herbarium. 

Huckleberry,  439. 

Humifuse :  spreading  flat  on  the  ground. 

Humus,  Humic  acid,  57. 

Hyaline :  transparent,  or  partly  so. 

Hybrid:  a  cross-breed  between  individ- 
uals of  two  species,  357. 

Hydrangiens,  425. 

Hydrocharidacese,  487. 

Hydroleacea?,  or  Hydrolese,  452. 

Hydrophyllaceae,  451. 

Hydrophyte :  a  water-plant. 

Hydropterides,  502. 

Hycmal :  belonging  to  winter. 

Hyinc'nium :  the  gills  of  Mushrooms,  &c, 
507. 

Hymcnophyllere,  501. 

Hypdnthium  :  a  naked  fleshy  receptacle, 
like  a  fig. 

Hypcricaceas,  394. 

Hypo-,  in  Greek  derivatives  :  under. 

Hypochilium  :  the  under  part  of  the  lip 
of  Orchids,  when  jointed  or  other- 
wise distinguishable. 

Hypocrateriform,  or,  moi-e  properly, 

Ilypocraterimdrphous  :  salver-shaped  ; 
i.  e.  with  a  limb  spreading  flat  at 
right  angles  to  the  tube;  277,  fig. 
457. 

Hypogceous,  or  hypogcean  (flowers  or 
fruits)  :  borne  under  ground,  76, 
78,  328. 

Hypdgynous:  growing  under  the  pistil, 
and  free,  250,  268,  280. 

Ilypophyllous :  growing  on  the  lower 
side  of  a  leaf. 

Hysteranthous :  plants  whose  leaves  ap- 
pear later  than  the  blossoms,  as 
the  Eed  Maple. 

Hysterophytal :  living  on  a  matrix,  either 
of  dead  or  living  organic  matter. 

Hysterophytes :  same  as  Fungi,  &c. 

Icos-,  in  Greek  compounds :  twenty. 

Icosandria,  512. 

Icosdndrous :  having  20  stamens  or  more 

inserted  on  the  calyx,  280. 
Illecebrese,  396. 
Imbibition,  177. 


GLOSSARY   AND    INDEX. 


537 


Imbricate,  imbricated,  imbrieative :  over- 
lapping, the  outer  covering  the  in- 
ner, and  breaking  joints,  like  tiles 
on  a  roof,  144,  269. 

Immarginate :  not  margined. 

Immersed:  growing  wholly  under  water. 

Impari-pinnate :  pinnate  with  an  odd 
leaflet;  163,  fig.  288. 

Imperfect  flowers:  wanting  either  sta- 
mens or  pistils. 

Impregnation :  same  as  fertilization. 

Inane:  empty. 

Incanous:  hoary-white. 

Incised:  cut  irregularly  and  sharply; 
159,  fig.  259. 

Included:  not  projecting  beyond;  en- 
closed. 

Incomplete  floicer :  wanting  some  one  or 
more  kinds  of  organs,  259. 

Incrassated :  thickened. 

Incrustations  in  cells,  58. 

1'ncubous :  the  apex  of  each  leaf  lying 
over  the  base  of  the  next,  as  in 
many  Hepaticre. 

Incumbent :  leaning  or  lying  upon : 
said  of  the  cotyledons  when  the 
radicle  lays  against  the  back  of  one 
of  them/  390,  326,  fig.  705  ;  or 
when  the  anther  lies  on  the  inner 
side  of  the  filament,  282. 

Incurred:  bent  or  curved  inwards. 

Indefinite:  either  uncertain  in  num- 
ber, or  too  many  to  be  readily 
counted,  242. 

Indefinite  growth,  100. 

ltd  finite  inflorescence,  210. 

Indchiscent  (fruits)  :  not  opening,  at 
least  not  in  a  regular  way,  310,  313. 

Indeterminate  inflorescence,  210. 

India-rubber,  57. 

Indigenous :  of  spontaneous  and  original 
growth  in  a  country. 

Indigo,  414,  415. 

Individual,  20,  131,  352. 

Individuality,  132,  352. 

Indumentum :  any  hairiness  or  downy 
covering. 

Indiiplicate:  bent  or  folded  inwards, 
145,  273. 

Indiisium :  the  proper  covering  of  the 
fruit-dots  of  Ferns ;  any  peculiar 
membranous  covering,  501. 

Inequilateral :  unequal-sided. 

Inferior:  underneath,  252;  or  same  as 
anterior :  thus  the  inferior  petal, 
&c.  is  the  same  as  the  anterior  one, 
237. 

Inflated:  bladdery. 

Indexed:  abruptly  bent  inwards. 

Inflorescence,  209. 

Infra-axillary:  originating  below  the 
axil. 


Infundibular,  infundibuliform :  funnel- 
shaped  ;  i.  e.  a  tube  enlarging  up- 
wards ;  277,  fig.  1049. 

Innate :  borne  directly  on  the  apex  of  a 
thing,  282. 

Innovations :  new  shoots  or  new  growths. 

Inorganic :  unorganized. 

Inorganic  constituents,  I'd. 

Inosculating :  opening  into  each  other ; 
anastomosing,  49. 

Inserted:  attached  to,  224,  250. 

Insertion:  the  place  or  the  mode  of  junc- 
tion of  leaves  with  the  stem,  &c., 
133. 

Inter-,  in  composition  :  between  ;  as 

Intercellular :  between  the  cells. 

Intercellular  spaces  or  passages,  24,  50. 

Intercellular  system,  50. 

Interlaced  tissue,  48. 

Internal  glands,  51. 

Internodes,  92. 

Interpe'tiolar :  between  the  petioles,  171. 

Interruptedly  pinnate,  164,  fig.  285. 

Intine:  the  inner  coat  of  a  pollen-grain. 

Intrafoliaceous :  within  or  before  a  leaf, 
171,  as  the  stipules  in  fig.  305. 

Introflexed:  bent  strongly  inwards. 

Intrdrse:  turned  inwards  towards  the 
axis,  282. 

Intruse:  appearing  as  if  pushed  inwards 
or  indented. 

Inverse:  inverted;  suspended. 

Involucellate :  furnished  with  an 

Involuce'llum,  or  involved:  a  secondary 
or  partial  involucre,  216. 

Involucrate :  provided  with  an 

Involucrum,  or  involucre :  an  outer  or 
accessory  covering  ;  a  set  of  bracts 
surrounding  a  flower-cluster ;  214, 
fig.  321,  &c. 

Involute :  rolled  inwards,  144,  273. 

Ipecacuanha,  393,  433. 

Iridacece,  490. 

Irregular  :  unequal  in  size  or  in  shape, 
253,  277. 

Irregularity,  253. 

Irritability,  345. 

Isdchroiis :  one-colored. 

Isoetineas,  502. 

Isdmerous,  or  isomeric :  the  parts  equal  in 
number. 

Isoste'monous :  the  stamens  as  many  as 
the  petals  or  sepals. 

Jalap,  455. 

Jasminacens,  459. 

Jelly,  55,  310. 

Jointed:  separate  or  separable  trans- 
versely into  pieces  (joints),  92. 

Juba:  a  loose  panicle,  as  of  Grasses. 

Juga :  the  ridges  of  the  fruit  of  Umbel- 
lifera3,  426. 


538 


GLOSSARY    AND    INDEX. 


Jugce :  the  pairs  of  partial  petioles  or 
leaflets  of  a  pinnately-compound 
leaf,  164. 

Juglandaceaj,  476. 

Jujube,  408. 

Julus :  a  name  for  a  catkin. 

Julaceous :  shaped  like  or  resembling  a 
catkin. 

Juncacea?,  495. 

Juncagineae,  487. 

Jungcrmanniacese,  505. 

Juniper-berries,  480. 

Jute,  400. 

Keel:  see  Carina,  254. 

Keeled:  furnished  with  a  keel  or  sharp 

ridge  underneath. 
Kernel  of  an   ovule,  297,  or  seed,  322. 
Key-fruit,  314. 
Kidney-shaped:  see  Kcniform  ;  157,  fig. 

245. 
Kingdom,  362,  15. 
Kinic  acid,  433. 
Kino,  414. 
Knot :  see  Node,  92. 
Knotted:  a  cylindrical  body  swollen  into 

knobs  at  intervals. 
Krameriacea:,  412. 

Labe'llum :  the  lip,  or  lower  petal  of  an 
Orchidcous  flower. 

Labiatse,  450. 

Labiate:  two-lipped,  278. 

Labiatiflorse,  436. 

Lac,  475. 

Laciniate :  slashed  ;  cut  into  narrow  in- 
cisions ;  these  are  called  laciniaz. 

Lactescent :  yielding  milky  juice. 

Ldcunose:  full  of  depressions  or  exca- 
vations (laciince). 

Lacustrine:  belonging  to  lakes. 

Ladanum,  394. 

Lcevigate :  smooth  as  if  polished. 

Lage'niform:  shaped  like  a  Florence 
flask  (lagena). 

Lalo,  399. 

Lame'lloz :  thin  plates,  like  the  gills  of  an 
Agaric,  507,  &c. 

Lamellar,  or  lamellate :  composed  of  fiat 
plates. 

Lamina  (a  plate)  :  the  blade  of  a  leaf, 
petal,  &c,  145, 276. 

Lanate,  lanose:  woolly;  i.  e.  clothed 
with  soft  interlaced  hairs. 

Lanceolate:  lance-shaped;  fig.  239. 

Lanuginous :  cottony  or  woolly. 

Latent  buds,  167. 

Lateral :  belonging,  or  attached  to,  the 
sides  of  an  organ. 

Latex :  milky  or  proper  juice,  49. 

L^aticiferous  tissue  or  vessels,  49. 

Lauracese,  or  Laurinese,  466. 


Lax:  loose;    the  opposite  of  close  or 

crowded. 
Layer  inq,  102. 
Leaf,  133. 

Leaf-arranaement  (phyllotaxis),  133. 
Leaf  bud,  72,  93. 
Leaf-green,  58. 
Leaflet :  a  separate  piece  or  partial  blade 

of  a  compound  leaf,  163. 
Leafstalk,  145,  170. 
Leaf-scars,  94. 
Leathery :  see  Foliaceous. 
Legume:  a  fruit  like  a  Pea-pod,  315. 
Legumine,  198. 

Leguminosag  (Leguminous  Plants),  412. 
Leguminous :  relating  to  legumes. 
Lemnaecae,  486. 
Lemon,  401. 
Lentibulacea?,  445. 
Lenticels:  little  spots  on  the  bark,  whence 

roots  often  issue. 
Lenticular :  lens-shaped ;  double-convex. 
Lentiginose:  freckled,  or  dusty-dotted. 
Leptus :  sterile  transformed  stamens. 
Lepidote :  leprous  ;  scaly  or  scurfy,  52. 
L,eucanthous :  white-flowered. 
Liber :  the  inner  fibrous  bark,  120,  127. 
Lid:  see  Operculum,  502. 
Lichenes  (Lichens),  505. 
Lichenology :  the  part  of  Botany  devoted 

to  Lichens. 
Licorice,  414. 

Ligneous:  woody  in  texture. 
Lignine,  36,  195. 
Lignum-vitaa,  405. 

Ligidate:  strap-shaped,  255 ;  having  a 
Ligule:  a  strap-shaped  corolla,  255,  fig. 

325,  d ;  the  appendage  between  the 

blade  and  the  sheath  of  the  leaf  in 

Grasses,  170. 
Ligulifloroe,  436. 
Liguliforous :  when  a  head  consists  of 

ligulate  flowers  only,  as  Cichory, 

fig.  323. 
Liliacese,  493. 
Liliaceous:  lily-like,  276. 
Limb  (limbus,  a  border)  ;    the  expanded 

part  or  border  of  a  corolla,  calyx, 

&c,  or  the  lamina  or  blade  of  a 

petal,  &c,  145,  276. 
Limbate :  bordered. 
Lime,  401. 
Limnanthaceoe,  404. 
Linacere,  402. 

LJne :  the  twelfth  of  an  inch.    (In  deci- 
mal measures,  the  tenth  of  an  inch.) 
Linear :  narrow  and  much  longer  than 

broad,  the  two  margins  parallel ; 

fig.  240. 
Lineate  :  marked  with  lines. 
Lineolate  :  marked  with  fine  or  obscure 

lines. 


GLOSSARY   AND    IXDEX. 


539 


Linguiform,  or  Ungulate:  tongue-shaped, 

as  the  leaves  of  Hound's-tongue. 
Lip:    the  two  lobes  a  bilabiate  calyx 

or  corolla ;  the  lower  petal  of  an 

Orchidcous  plant. 
Littoral,  or  litoral:  growing  on  shores. 
Livid :  pale  lead-color. 
Loasacete,  421. 
Lobe :  any  division  or  projecting  part 

of  an  organ,  especially  a  rounded 

one,  275. 
Lobed,  lobate :    divided  into  lobes ;  fig. 

260,  264. 
Lobeliacere,  438. 

Ldbulate :  bearing  small  lobes  (lobuli). 
Ldcellate:   having   secondaiy  cells    (or 

locelli). 
Loce'llus    (plural,  locelli)  :   a  secondary 

cell,  or  a  division  of  a  cell. 
Ldculament,  316  ;  same  as  loculus. 
Ldcular :  having  cells. 
Loculicidal,    or    loculicide  :    dehiscence 

opening  directly  into  the  back  of  a 

cell;  316,  fig.  583,  585. 
Ldculose :  partitioned  off  into  cells,  as 

the  pith  of  Poke,  &c. 
Loculus   (plural,  loculi):  the  cells  of  an 

ovary,  anther,  &c. 
Lociista  :  a  spikelet  or  flower-cluster  of 

Grasses. 
Lddicules  (lodiculce);  the  minute  scales 

inside  of  the  paleae  of  Grasses,  497. 
Loganiaceas,  433. 
Logwood,  414. 
Loment:  a  jointed   legume;    315,   fig. 

581. 
Lomentaceous :  bearing  or  resembling  a 

loment. 
Longitudinal  tissue  or  system,  45,  50,  112. 
Lonicerere,  431. 
Loranthacea?,  469. 
Lorate :  thong-shaped. 
Lucid:  shining. 

Lunate :  crescent  or  half-moon  shaped. 
Liinulate  :  diminutive  of  the  last. 
LMpuline  :  waxy  grains  on  the   scales 

of  Hops. 
Lurid:  dingy  brown. 
Lutescent :  yellowish.    (Luteus :  yellow). 
Lycopodiacese,  501. 
Lycdtropous,  or  lycdtropal :  an  orthotro- 

pous   ovule  curved  into   a  horse- 
shoe form. 
Lyrate,  lyre-shaped,  161,  fig.  138,  278. 
Lyrately  pinnate,  164,  fig.  285. 
Lythraceae,  or  Lythariea?,  418. 

Mace:  the  arillus  of  Nutmeg,  322,  383. 
Maculate :  spotted  or  blotched. 
Madder,  432. 
Magnoliaceas,  381. 
Mahogany,  401. 


Maize,  498. 

Male  flower,  261. 

Malp'ighiaceae,  409. 

Malpighiaceous   hairs:   hairs    fixed    by 

their  middle,  as  in  the  foregoing 

order,  in  Cornus,  &c. 
Malvaceae,  397. 
Mdmillate,  or  mdmillar :   bearing   little 

prominences  on  the  surface. 
Mdmmceform :  teat-shaped. 
Mammee-apple,  400. 
Mammose :  bearing  larger  prominences, 

like  breasts. 
Mango,  406. 
Mangosteen,  400. 
Manicate   (gloved) :    covered    with    a 

woolly  coat  which  may  be  stripped 

off  whole. 
Manilla  hemp,  490. 
Manna,  460. 
Many-cleft :  cut  as   far  as  the   middle 

into  several  divisions,  159. 
Many-headed :  see  Multicipital. 
Marantaceae  :  see  Cannacese. 
Marcescent:  gradually  withering  with- 
out falling  off,  279. 
Marchantiacese,  504. 
Marginal :  belonging  to  the  margin. 
Marginate :  furnished  with  a  margin  of 

different  texture  or  color  from  the 

rest. 
Maritime :  belonging  to  the  sea-shore. 
Markings  on  cells,  3,  6. 
Marmorate :  marbled. 
Marsiliacese,  502. 
Mas :    male,  masculine  ;   belonging  to 

the  stamens. 
Masked:  see  Personate,  278. 
Mealy :  see  Farinaceous. 
Medial:  belonging  to  the  middle. 
Medulla:  pith,  118. 
Me'dullary  rays,  117,  119. 
Medullary  sheath,  119. 
Medullose,  or  medullary :  pith-like. 
Meioste'monous :   having  fewer  stamens 

than  petals. 
Melanospermese,  509. 
Melanthaces,  494. 
Melastomacea?,  418. 
Meliacese,  401. 
Melon,  423. 
Membranaceous,  or  membranous:  thin  and 

soft,  like  a  membrane. 
Meniscoid:   shaped  like  a  meniscus  or 

concavo-convex  lens. 
Menispermaceas,  383. 
MenyanthideaB,  457. 
Mere'nchyma,  41. 

Me'ricarp:  half  a  cremocarp,  426. 
Merismdtic:  dividing  into  parts,  28. 
Me'rithall :  a  name  for  an  internode. 
Merous,  in  Greek  compounds  :  the  parts 


540 


GLOSSARY    AND    INDEX. 


of  a  flower :  sec  Dimerous,  Trime- 
rous,  &c. 

Mesembryanthemacea3,  397. 

Me'socarp :  the  middle  layer  of  a  peri- 
carp, 310. 

Mesophldum  :  the  middle  bark  or  green 
layer,  121. 

Mesophyllum  :  the  parenchyma  of  a  leaf 
between  the  skin  of  the  two  sur- 
faces. 

Metamorphosed:  that  which  has  under- 
gone. 

Metamorphosis :  the  transformation  of 
one  or^an  into  another  homologous 
one,  228,231. 

Micropyle:  the  orifice  of  a  seed,  29S. 

Midrib :  the  central  or  main  rib,  155 

Milky  juice,  49. 

Mimoseffi,  413. 

Mineral  constituents  of  plants,  179. 

Miniate :  vermilion-color. 

Mitriform :  mitre-shaped,  503. 

Molluginea;,  395. 

Monadclphia,  513. 

Monadelphous :  with  filaments  united 
into  a  tube,  or  ring ;  280,  fig.  462. 

Monandria,  512. 

Mondndrous :  with  a  single  stamen,  279. 

Mondnlhous :  one-flowered. 

Monihform  :  nceklacc-shaped  ;  cylin- 
drical and  contracted  at  intervals. 

Monimiacese,  382. 

Monkey-bread,  399. 

Mono-,  in  Greek  compounds :  one  or 
single. 

Monocdrpellary  :  of  one  carpel. 

Monocdrpic,  or  monocdrpian  :  once-fruit- 
ing, 101. 

Monocephalous  :  bearing  a  single  head. 

Monochlamydeous :  with  a  single  floral 
envelope  ;  i.  c.  apetalous,  260. 

Monoclinous :  hermaphrodite. 

Monocotyle'donous :  one-cotyledbned,  79, 
326. 

Monocotyledons  or  Monocotvledonous 
Plants,  113,  326,  370,  482. 

Moi'oecia,  513. 

Monoecious :  stamens  and  pistils  in  sep- 
arate flowers  on  the  same  individ- 
ual, 262. 

Monogamia,  516. 

Monogynia,  515. 

Mondgynous:  with  one  pistil  or  style,  287. 

Monoicous :  same  as  monoecious. 

Mondmerous:  the  parts  of  the  flower 
single,  234. 

Monope'talous :  one-petalled,  but  it  is 
used  for  gamopetalous,  viz.  petals 
more  or  less  united  into  one  bodv, 
249,  275. 

Monophyllous :  one-leaved,  of  one  piece, 
275. 


Mondpterous :  one-winged. 

Monopyrenous :  one-stoned. 

Monosepalous :  the  calyx  of  one  piece, 
249. 

Monospe'rmous :  one-seeded. 

Mondstichous  :  in  one  vertical  rank, 
134. 

Hfondsfylous  :  with  one  style. 

Monotropeas,  or  Monotropaceie,  440. 

Monster,  monstrous  (430) :  developed  in 
an  unnatural  manner. 

Morphine,  57. 

Morphology,  14,  60,  224. 

Mdrphosis :  the  manner  of  development. 

Moschate  :  exhaling  the  odor  of  musk. 

Moulds,  65. 

Mucilage :  dissolved  vegetable  jelly,  or 
dextrine,  55,  193. 

M^ucilaginous,  mucose,  or  mucous:  slimy. 

Mucro :  a  short,  sharp  point. 

Mucronate:  abruptly  tipped  with  a  mu- 
cro ;  162,  fig.  2*76,  231. 

Mucrdnulate:  tipped  with  a  minute  mu- 
cro. 

Mulberry,  475. 

Mule :  a  hybrid. 

Multangular :  many-angled. 

Multi-,  in  Latin  derivatives  :  many;  as, 

Multicipital  (nuilticeps)  :  many-headed; 
where  several  buds  or  shoots  pro- 
ceed from  the  crown  of  one  root. 

Multifarious :  many-sided. 

Multi  fid:  many-cleft,  159. 

M^ultifidrous :  many-flowered. 

Multijugate :  in  many  pairs. 

Multildcular :  many-celled. 

Multiple :  compound. 

Multiple  fruits,  309,  318. 

Multise'rial :  in  several  horizontal  ranks. 

Multiseptate :  many-partitioned. 

Miiricate:  rough  with  short  and  hard 
points. 

Muriculate :  minutely  muricate. 

Musaceas,  490. 

Muscardine,  508. 

Muscariform :  brush-shaped. 

Musci  (Mosses),  502. 

Musciform :  moss-like. 

Muscology:  the  department  of  Botany 
which  treats  of  Mosses. 

Mustard,  389. 

Miiticous  :  pointless  ;  blunt. 

Mi/celium,  507. 

Mycology,  or  Mycetdlogy :  the  depart- 
ment of  Botany  which  treats  oiv 
Fungi. 

Mycropyle :  see  Micropyle. 

Myricaceee,  477. 

Myrsinacese,  443. 

Myristicaceae,  383. 

Myrrh,  407. 

MyrtacesE,  418. 


GLOSSARY    AND    INDEX. 


541 


Naiadaccae,  487. 

Naked  flowers :  same  as  achlamydeous ; 
or  destitute  of  involucre,  &c. 

Naked  ovules  and  seeds,  296,  320. 

Karnes  of  species  and  genera,  363 ;  of 
orders,  tribes,  &c,  373. 

Ndpiform:  turnip-shaped,  84. 

Natant:  floating  under  water. 

Natural  system,  365,  366. 

Naturalized:  species  introduced,  but 
growing  completely  spontaneous, 
and  propagating  by  seed. 

Navicular :  boat-shaped . 

Nelmlose  :  clouded. 

Neck:  the  junction  of  root  and  stem. 

Necklace-shaped:  see  Moniliform. 

Nectar :  the  honey  of  a  flower,  or  any 
sweetish  exudation. 

Nectary  (nectarium)  :  a  place  or  thing 
in  which  nectar  is  secreted  :  for- 
merly applied  also  to  any  anoma- 
lous part  or  appendage  of  a  flower, 
whether  known  to  secrete  honey  or 
not,  as  to  the  spur-shaped  petals  of 
Aquilegia,  fig.  647,  or  the  two 
singular-shaped  petals  of  Aconi- 
tum,  257,  fig.  402,  404. 

Needle-shaped :  see  Acerose. 

Nelumbiaceae  (Nelumbo),  385. 

Nemeous :  filamentose ;  composed  of 
threads. 

Nervation :  the  arrangement  of  the 

Nerves:  parallel  and  simple  veins. 

Nerved :  nervate ;  furnished  with  nerves, 
154. 

Nervose :  abounding  in  nerves. 

Netted:  same  as  reticulated. 

Nelted-veined,  1 54. 

Neurose :  same  as  nervose. 

Neutral :  without  sexes. 

Neutral  flowers :  having  neither  stamen 
nor  pistil,  263,  436. 

Neutral  quaternary  products,  196. 

New  Zealand  Hemp,  492. 

Niduhmt :  nestling  in. 

Nitid  (nitidus) :    smooth  and  shining. 

Niveous :  snow-white. 

Nodding:  curved  so  that  the  apex 
hangs  down. 

Node  (knot)  :  the  place  on  a  stem 
where  a  leaf  is  attached,  92. 

Nodose :  knotty  ;  swollen  in  some  parts, 
contracted  at  others. 

Nodulose:  diminutive  of  the  last. 

Normal :  according  to  rule. 

Notate :  marked  by  spots  or  lines. 

Notorhizal :  the  radicle  bent  round  to 
the  back  of  one  cotyledon ;  same 
as  incumbent. 

Niirumentaceous :  nut-like. 

Niicelle :  same  as  nucleus. 

Nut-form :  nut-like. 

46 


Nucleus:  the  kernel,  297,  320,  322. 

Nucleus  of  a  cell,  26. 

Nuculanium  :  a  name  for  a  berry  like  a 
grape. 

Nucule :  a  diminutive  nut,  stone,  or 
kernel. 

Niiculose:  containing  nucules  or  nut- 
lets. 

Numerous:  same  as  indefinite. 

Nut,  314. 

Nutlet :  a  small  nut,  or  the  small  stone 
of  a  berry -like  drupe. 

Nutmeg,  383. 

Nutant :  nodding. 

Nutrition,  61,  177. 

Nux- vomica,  434. 

Nyctaginacea;,  463. 

Nymphaaaeeas,  385. 

Oat,  498. 

Ob-  (over  against)  signifies  inversely; 
as, 

Obcom pressed :  flattened  fore  and  aft,  in- 
stead of  laterally. 

Obcdrdate :  heart-shaped  inverted ;  1 62, 
fig.  274,  233. 

Obldnceolate :  lance-shaped,  but  broader 
upwards. 

Oblique,  referring  to  shape,  unequal- 
sided,  165. 

Obliteration,  309. 

Oblong:  elliptical,  or  approaching  it, 
and  much  longer  than  wide  ;  fig. 
242. 

Obdvate:  inversely  ovate ;  157,  fig.  232. 

Obtuse:  blunt;  the  apex  an  obtuse  an- 
gle; 162,  fig.  270,  236. 

Obverse:  same  as  ob. 

O'bvolute :  a  modification  of  convolute, 
145. 

Oce'llate :  eyed ;  a  circular  patch  of 
,      color  within  another  patch. 

Ochrea  (a  boot)  :  a  tubular  stipule ; 
,      171,  fig.  305. 

Ochreate :  furnished  with  ochrcee. 

Ochroleiicous :  ochre-colored  (pale  dull 
yellow)  verging  to  white. 

Octo- :  eight ;  in  composition  in  such 
words  as  the  following. 

Octagijnia,  515. 

Octdgi/nous :  with  eight  pistils  or  styles. 

Octdmerous :  the  parts  in  eights. 

Octandria,  512. 

Octdndrous :  with  eight  stamens. 

Octope'talous :  of  eight  petals,  276. 

O'culate:  eyed;  same  as  ocellate. 

Officinal  (belonging  to  the  shop)  :  ap- 
plied to  plants,  &c.  used  in  medi- 
cine or  the  arts. 

Offset,  102. 

Oilnut,  469. 

Oils,  56,  57. 


542 


GLOSSARY    AND    INDEX. 


Okra,  398. 

Oleaccas,  459. 

Oleraceous :  of  the  nature  of,  or  fit  for, 
pot-herbs. 

Oligo-,  in  Greek  derivatives  :  few  ;  as 

Oligandrous :  having  few  stamens. 

Olirjospe'rmous :  few-seeded. 

Olive,  Olive-oil,  4G0. 

Onagraceae,  419. 

One-celled  plants,  61. 

One-sided:  see  Secund  and  Unilateral. 

Oophoridia :  the  larger  and  compound 
spores  of  Lycopodiaceas. 

Opaque :  the  reverse  of  shining  ;  dull. 

Ope'rculate :  furnished  with  a  lid  or 

Operculum:  a  lid,  such  as  that  of  the 
spore-case  of  Mosses,  502. 

Ophioglosscaj,  501. 

Opium,  389. 

Opposite  (leaves,  &c.) :  opposed  to  alter- 
nate, that  is,  placed  over  against 
each  other,  78,97,  133,  141.  A 
stamen,  &c.  is  said  to  be  opposite 
a  petal,  when  it  stands  before  it 
(248),  as  in  fig.  435  and  670. 

Oppositifolious :  opposite  a  leaf,  as  the 
tendrils  of  Vitis,  fig.  767,  and  the 
peduncles  of  Phytolacca,  fig.  1086. 

Orange,  401. 

Orbicular :  circular  in  outline. 

Orchidaceae,  488. 

Orders,  359. 

Ordinal :  relating  to  orders. 

Organic  constituents,  179,  180. 

Organization,  17. 

Organography,  14,  60. 

Organogeny  :  the  development  or  for- 
mation of  organs,  268. 

Organs,  18. 

Organs  of  Reproduction,  70. 

Organs  of  Vegetation,  68,  70,  204. 

Orobanchaceae,  446. 

Orris-root,  491. 

Ort/iopldceous  (embryo)  :  with  incum- 
bent and  conduplicate  cotyledons, 
as  in  Mustard. 

Orthdtropous,  or  orthdtropal  ovule  ;  298, 
fig.  526.  The  term  when  applied 
to  the  embryo  is  used  as  the  con- 
trary of  antitropous,  i.  e.  having 
the  radicle  next  the  hilum,  as  in 
an  anatropous  seed. 

Osage  Orange,  475. 

Osmundaceaj,  or  Osmundinese,  501. 

Osseous :  of  the  texture  of  bone. 

Ouari  Poison,  434. 

Oval:  broadly  elliptical;  157,  fig.  229. 

O'vury  :  the  ovule-bearing  portion  of  a 
,       pistil,  223,  287. 

Ovate  :  egg-shaped,  or  like  the  longitu- 
dinal section  of  an  egg,  fig.  241. 

Ovoid :  a  solid  ovate  or  oval. 


Ovulate,    ovuled,    or   ovuliferous :    bear- 
,      ing  ovules. 
Ovule :   an  unimpregnated  seed  or  body 

destined   to   become  a  seed,  223, 

297. 
Oxalidaccae,  404. 

Palate :  an  inward  projection  of  the 
lower  lip  of  a  personate  corolla; 
278,  fig.  459,  460. 

Pdlea,  or  palet :  a  chaff ;  one  of  the 
bracts  on  the  receptacle  of  Com- 
posite, 215,  435  ;  one  of  the  inner 
bracts  or  glumes  of  Grasses,  497. 

Paleaceous  :  chaff-like,  or  bearing  chaff. 

Pa/e'ola  :  diminutive  of  palea ;  one  of 
the  minute  innermost  scales  of  the 
flower  of  Grasses.  See  Squa- 
mella. 

Palmae  (Palms),  484. 

Palmate :  lobed  or  divided  so  that  the 
sinuses  all  point  to  the  apex  of  the 
petiole,  either  moderately,  as  in  a 
Maple-leaf,  or  so  as  to  make  the 
leaf  compound,  as  in  Horsechest- 
nnt,  when  it  is  the  same  as  Digitate ; 
161,  163, 164. 

Palmalely  lobed,  cleft,  parted,  &c,  161. 

Palmalely  2  -  plurifoliolate,  164. 

Palmate! >/  veined,  156. 

Palmdtifid:  pal mately  cleft ;  fig.  265. 

Palmdtisect :  palmatcly  divided ;  fig. 
267. 

Paludose,  palustrine :  inhabiting  marshes. 

Pandanacea?,  485. 

Pdndurate,  or  pandiiriform :  same  as 
fiddle-shaped. 

Panicle  :  a  raceme,  branched  irregular- 
ly; 216,  fig.  326. 

Panic/cd,  or  paniculate:  arranged  in  a 
panicle. 

Papaveracete,  388. 

Papaw,  383,  422. 

Papayaceae,  422. 

Papery :  of  the  consistence  of  letter- 
paper. 

Papilionaceae,  413. 

Papilionaceous:  butterfly-like,  253. 

Papillose,  or  papillate :  bearing  small, 
soft  projections  (papillae,  nipples 
or  pimples). 

Pappose,  or  pappiferous :  bearing  a 

Pappus  (thistle-down),  260,  314,  435. 

Papyraceous :  papery. 

Papyrus,  496. 

Paracorolla :  an  appendage  or  duplicate 
of  a  corolla,  such  as  was  once 
called  a  nectary. 

Parallel-veined  or  nerved,  154. 

Pardphgsis :  jointed  thread-like  bodies 
accompanying  the  pistillidia  of 
Mosses. 


GLOSSARY   AND    INDEX. 


543 


Parasitic  plants,  or  Parasites:  living  on 

the  juices  of  other  plants,  88. 
Parastemon :  same  as  Staminodium. 
Parenchyma:  soft  cellular  tissue,  41. 
Parietal :  attached  or  belonging  to  the 

walls,  292. 
Parietes  :   -walls  of  an  ovary,  &c. 
Paripinnate:  same  as  abruptly  pinnate, 

163. 
Parnassiacere,  394. 
Parsnip,  426. 
Parted,  or  partite :  cut  almost  through ; 

160,  fig.  262,  266. 
Partial  peduncle,  211. 
Partial  pet  iole,  164. 
Partial  umbel,  216. 
Parthenogenesis,  300,  340. 
Passifloracese  (Passion-flowers),  422. 
Patelliform :  kneepan-shaped. 
Patent :  spreading  wide  open. 
Patulous :  moderately  spreading. 
Pauci-,  in  Latin  derivatives  :  few ;  as 
Paucijldrous :  few-flowered. 
Peach,  415. 
Pear,  416. 
Pear-shaped :    ovoid  at  the  extremity, 

conical  at  the  base. 
Pe'ctinate :  pinnatifid  with  close-set  and 

equal  lobes,  like  the  teeth  of  a  comb 

(pecten),  160. 
Pcctine,  and  Pectic  acid,  55,  310. 
Pedate  :  palmate,  with  the  lateral  lobes 

asjaiu  lobed  ;  appearing  like  a  bird's 

foot,  161,  fig.  249. 
Pedately :  in  a  pedate  mode. 
Pe'dicel :  the  stalk  of  a  particular  flower, 

211. 
Pedicellate,  pedicelled:    having  a  pedi- 
cel. 
Peduncle :    a   flower-stalk    in   general. 

either  of  one  blossom  or  a  whole 

cluster,  211. 
Pedunculate-,  peduncled :    having  a    pe- 
duncle. 
Peloria,  278. 
Peltate :    shield-form  or  target-shaped  ; 

fixed  by  the  centre  or  some  part 

of  the  lower  surface  ;  fig.  248,  681. 
Peltinerved :  peltately  veined. 
Pelviform :  open  cup-shaped. 
Pendent,  pendulous :  hanging  down. 
Penicillate,  penicilliform :  tipped  with  a 

brush  of  hairs,  like  a  camel's-hair 

pencil. 
Parnate:  same  as  pinnate. 
Penniform :  feather-like. 
Penninerved :  same  as  pinnately  nerved 

or  veined. 
Penta-,  in  Greek  derivatives  :  five  ;  as 
Pentacdrpellary :  of  five  carpels. 
Pentacdccous :  of  five  cocci. 
Pentagynia,  515. 


Pentdqynous  :  with  five  pistils  or  styles, 
287. 

Pentdmerous :  of  five  parts  ;  234,  239, 
fig.  354. 

Pentandria,  512. 

Pentdndrous  :  having  five  stamens,  279. 

Pentapetalous :  of  five  petals,  276. 

Pentaphyllous :  five-leaved,  275. 

Pentdpterous :  five-winged. 

Pentasepalous :  of  five  sepals,  274. 

Pentdstichous :  in  live  vertical  ranks, 
135. 

Pepo:  a  Gourd-fruit,  312. 

Pepper,  456,  469. 

Perennial:  lasting  year  after  year,  84. 

Perfect  flower :  one  having  both  stamens 
and  pistils,  261. 

Perfoliate:  when  the  stem  appears  to 
pass  through  the  leaf;  165,  fig. 
293.  294. 

Perforate :  pierced  with  holes,  or  having 
transparent  dots  which  look  like 
holes. 

Pergame'neous,  or  pergamentdceous  :  like 
parchment. 

Peri-,  in  Greek  derivatives  :  around. 

Pe'rianih  (peridnthium)  :  the  floral  en- 
velopes collectively,  either  of  one 
set  (calyx)  or  of  two  sets  (calyx 
and  corolla),  222. 

Pericarp  :  the  ovary  in  fruit,  308. 

Pericdrpic ;  belonging  to  the  pericarp. 

Perichatial :   relating  to  the 

Pe'richazlh,  or  perichatium :  the  cluster 
of  peculiar  leaves  surrounding  the 
base  of  the  fruit-stalk  of  Mosses. 

Pcriclinium :  a  name  for  the  involucre 
of  Composite. 

Pe'riderm  :  same  as  Epiphlceum. 

Pe'rigone,  or  perigonium :  same  as  Peri- 
anth. 

Perigynium  :  bristles  or  other  organs,  of 
doubtful  nature,  around  the  pistil  in 
Cyperacea:,  497. 

Perigynous :  borne  on  the  calyx  ;  liter- 
ally around  the  ovary ;  i.  e.  when 
the  petals  or  stamens  are  adnate  to 
the  base  of  the  ovary  or  to  the 
calyx  ;  251,  268,  fig.  3S8,  3S9,  281. 

Peripetalous  :  around  the  petals. 

Peripheric:  surrounding  the  circumfer- 
ence, 325  ;  as  the  embryo  around 
the  albumen  in  fig.  621. 

Pe'risperm :  the  albumen  of  the  seed, 
322,  or  that  albumen  which  is 
formed  in  the  tissue  of  the  nucleus, 
323. 

Pe'ristome,  502. 

Peritropous,  peritropal  (seed)  :  horizon- 
tal to  the  axis  of  the  fruit. 

Perpendicular  system  of  the  stem,  112. 

Persimmon,  443. 


544 


GLOSSARY    AND    INDEX. 


Persistent :  remaining,  as  the  leaves  of 

evergreens  through  the  winter,  172 ; 

and  the  calyx,  &c.  of  many  plants 

until  the  fruit  is  formed,  279. 
Pe'rsonate :     masked  ;     278,    fig.    459, 

460. 
Pertuse :  having  slits  or  holes. 
Pe'rulate:  having  peruke  or  bud-seales. 
Peruvian  Bark,  432. 
Petal :  a  leaf  of  the  corolla,  222. 
Petalme,  or  pe'tcdoid:  petal-like,  in  color 

and  texture,  260. 
Pe'tiolar  :  borne  on  the  petiole. 
Pe'tiolate,  petioled :  having  a  petiole. 
Petiole:  leafstalk,  145,  170. 
Petidlulate:  the  leaflet  stalked,  164. 
Petiolule:  the  stalk  of  a  leaflet,  164. 
Phcendgamous,  or  phanerdgamous :  hav- 
ing manifest  flowers,  69. 
Phoenogamous      or      Phanerogamous 

Plants,  69,  369,  375. 
Phalanges:    bundles    of  adelphous    or 

clustered  stamens. 
Phordnthium :   the  receptacle  of  Com- 

positae. 
Phrymacese,  450. 
Phyrdlogy :  same  as  Algology. 
Phylla:  leaves,  274.     -phyllous  :  leaved, 

as  3-phyllons,  three-leaved,  &c. 
Phyllodtneous :  bearing  or  resembling  a 
P/iyllddium :    a   dilated   petiole  taking 

the  place  of  a  blade,  170. 
Phylhtdxis,  or  phyllatdxy,  133. 
Physiological  Botany,  14,  17. 
Phytelephantere,  485. 
Phytdgraphy :  descriptive  Botany. 
Phytolaecacece,  463. 
Phytdlogy  :  Botany  in  general. 
Phyton  :  a  simple   plant-individual,  or 

plant-element,  96. 
Phytdtomy :  vegetable  anatomy,  14. 
Pileale,  pileiform :  like  a  cap  or 
Pilots,  507. 
Pileorhiza  :  the  cap  of  a  root,  as  found 

in  some  aquatic  plants  ;  fig.  102. 
Piltferous :  bearing  or  tipped  with  hairs 

[pili). 
Pilose ;    hairy,   as   distinguished  from 

woolly  or  downy  ;  i.  c.  distinct  and 

straight,  but  not  rigid  hairs. 
Pilosity :  hairiness. 
Pimento,  418. 
Pine-apple,  492. 
Piney  Tallow,  400. 
Pink-root,  435. 
Pinna :  one  of  the  primary  divisions  of 

a  pinnatcly  compound  leaf,  164. 
Pinnate,  pinnated:    a   compound    leaf 

with   leaflets    arranged   along    the 

sides  of  a  common  petiole  ;    163, 

fig.  288-290. 
Pinnately  cleft,  lobed,  parted,  &c,  160. 


Pinnately  3-plurifoliolate,  &c,  164. 

Pinnately  veined,  155,  160. 

Pinndtijid:  pinnately  cleft;  fig.  261. 

Pinndtisect:  pinnately  divided;  fig. 
263. 

Pinnule :  a  secondary  division  of  a  pin- 
nately compound  leaf. 

Piperacese,  469. 

Piperine,  469. 

Pisiform :  pea-shaped. 

Pistachio-nut,  406. 

Pistil:  the  ovule-bearing  organ  of  a 
flower,  223,  287. 

Pistillate  :  furnished  with  pistils,  or  pis- 
tils only,  261. 

Pistillidium,  337. 

Pitch,  480. 

Pitchers:  see  Ascidium  ;  169,  387,  fig. 
299-301. 

Pitcher-shaped :  campanulate  or  tubular, 
but  with  a  narrower  mouth. 

Pith,  118. 

Pits,  37. 

Pitted :  marked  with  small  depressions. 

Pitted  tissue,  45. 

Placenta :  the  place  or  part  of  the  ovary 
which  bears  the  ovides  or  seeds, 
289. 

Placentation :  the  arrangement  of  pla- 
centa?. 

Placentiferous :  bearing  the  placenta;. 

Placdntiform  :  nearly  the  same  as  quoit- 
shaped. 

Plaited:  see  Plicate,  273. 

Plane:  flat. 

Plantaginacea3,  444. 

Platanacea;,  476. 

Platycdrpous :  broad-fruited. 

Pleio-,  in  Greek  derivatives  :  full  of,  or 
many ;  as 

Pleiospermous  :  many-seeded,  &c. 

Pleure'nchyma  :  woody  tissue,  41. 

Pleurorhizal :  embryo  with  the  radicle 
lying  against  the  side  or  edge  of 
the  cotyledons ;  same  as  accum- 
bent. 

Plicate,  plicative  :  thrown  into  longitu- 
dinal plaits  (plicie);  folded,  144, 
273. 

Plum,  415. 

Plumbaginacea;,  444. 

Plumose :  feathered  ;  when  bristles,  &c. 
have  fine  hairs  on  each  side  like 
the  plume  of  a  feather,  as  the  pap- 
pus of  Thistles,  &c. ;  fig.  890. 

Plumule :  the  bud  or  growing  point  of 
the  embryo  above  the  cotyledons, 
71,  324. 

Pluri-,  in  words  of  Latin  origin :  sev- 
eral, at  least  more  than  one ;  as 

Plurifidrous :  several-flowered. 

Plurifdliolate :  bearing  several  leaflets. 


GLOSSARY   AND    INDEX. 


545 


Plurildcular :  several-celled. 
Pdculiform :  deep  cup-shaped. 
Pod:  a  dry  dehiscent  fruit,  315. 
Pddosperm:  seed-stalk,  297. 
Podostemacea3,  471. 
Pointless :  see  Muticous. 
Poiniletted:  same  as  Apiculate. 
Polemoniacece,  453. 
Pollen :  the  contents  of  the  anther,  223, 

285. 
Pollen-tube,  286,  302. 
Pollinia  :  pollen-masses,  286,  489. 
Polliniferous :  bearing  pollen. 
Poly-,  in  Greek  compounds  :  numerous. 
Polyadelphia,  513. 
Polyadelphous :  having  the  filaments  in 

several  sets,  280. 
Polyandria,  512. 
Polydndrous  :   with  numerous  stamens, 

especially  when   inserted    on    the 

receptacle,  242,  280. 
Polydnthous :  many-flowered. 
Polycdrpic:  fruiting  many  times,  i.  e. 

year  after  year;  perennial.  101. 
Polyce'phalous  :  bearing  many  heads. 
Polycladous :  much-branched. 
Polycdccous :  of  several  cocci. 
Polycotyle'donous :  having  several  cotyle- 
dons, 79,  326. 
Polygalacese,  411. 
Polygamia,  513,  515. 
Polygamous :  having  both  perfect  and 

separated  flowers,  262. 
Polygonacea?,  465. 
Polygonous :  many-angled. 
Polygyria,  515. 
Polygynous:    with  numerous  pistils   or 

styles,  287. 
Polymerous:  formed  of  many  members. 
Polymorphous  :  various  in  form. 
Polypeta/ous :    having   distinct    petals, 

249,  275. 
Pdlyphore ;    a  common    receptacle    of 

many  carpels,  as  in  Strawberry. 
Polyphyllous :     many-leaved  or  several- 
leaved,  275. 
Polypodiacea;,  or  Polypodinese,  501. 
Polyrhizal :  many-rooted. 
Polysepalous :  of  two  or  more  distinct 

sepals,  249,  275. 
Polyspe'rmous :  many-seeded. 
Polysporous:  containing  many  spores. 
Polyste'monous  :  with  many  stamens. 
Pome:  an  apple,  pear,  &c,  312. 
Pomeee,  or  Pomacese,  416. 
Pomegranate,  418. 
Pomiferous :  pome-bearing. 
Pomology:    the  department  of  Botany 

relating  to  fruits. 
Pontederiacese,  495. 
Porose:  porous,  having  holes. 
Portulacaccaj,  396, 

46* 


Posterior  (in  the  flower) :  next  the  com- 
mon axis,  237. 

Pdsticous:  same  as  extrorse. 

Potato,  456,  455. 

Pouch:  see  Silicle,  317. 

Prafloration  :  same  as  ^Estivation,  269. 

Pra-foliation :  same  as  Vernation,  143. 

Praimdrse :  as  if  bitten  off. 

Prickly :  armed  with 

Prickles,  52. 

Primine :  outer  coat  of  the  ovule,  298. 

Primordial  leaves,  143  ;  utricle,  26. 

Primulaceffl,  443. 

Prismatic,  prismatical :  with  flat  longi- 
tudinal faces,  separated  by  angles. 

Process :  any  projection  from  a  surface. 

Procumbent :  lying  along  the  ground, 
102. 

Produced :  prolonged  or  extended. 

Pro-embryo,  338. 

Proliferous  (bearing  offspring) :  develop- 
ing new  branches,  flowers,  &c.  from 
the  older  ones,  or  from  unusual 
places. 

Prone :  lying  face  downwards. 

Proper  juices,  57. 

Prose'nchyma,  41. 

Prose'nthesis,  236. 

Prostrate :  lying  flat  on  the  ground,  102. 

Proteaceag,  468. 

Proteine,  27,  53,  57,  196. 

Proterdnthous :  where  flowers  arc  pro- 
duced earlier  than  the  leaves. 

Prothdllus,  or  protothallus,  338. 

Protophytes  :  Algae  and  Lichenes  are 
so  called. 

Protoplasm,  26,  53,  57,  196. 

Priiinate,  priiinose :  as  if  frosted  over. 

Pi-uniform :  plum-shaped. 

Pseudo-bulb :  a  kind  of  corm,.as  of  epi- 
phytic Orchidaceae. 

Pseudo-parasitic:  same  as  epiphytic. 

Pterocdrpous :  wing-fruited. 

Pteroid:  wing-like. 

Pube'scent :  clothed  with  soft  or  downy 
hairs,  or  pubescence. 

Puqidniform  :  dagger-shaped. 

Pulque,  491. 

Pulse,  413. 

Pulveraceous,  or  pidve'rulent :  dusty  or 
powdery  on  the  surface. 

Puh'inate :  cushioned. 

Pulvinus  (a  cushion)  :  an  enlargement 
at  or  below  the  base  of  a  leafstalk. 

Pumpkin,  423. 

Punctate:  dotted  as  if  by  punctures. 

Pungent :  pricking  ;  rigid-pointed. 

Piistulate :  blistered. 

Putdmen :  the  stone  or  shell  of  a  drupe, 
310,  312. 

Pyre'nce :  the  stones  of  small  drupes  ; 
same  as  nucules. 


546 


GLOSSARY   AND    INDEX. 


Piriform :  pear-shaped. 
Pyroleas,  or  Pyrolacese,  440. 
Pyxidate :  furnished  with  a  lid,  like  a 
Pyxidium,  or  pyxis :  a  pod  opening  by  a 
lid;  317,  fig.  575,  588,  950,  &c. 

Quadrangular :  four-angled. 

Quadri-,  in  Latin  compounds  :  four. 

Quadrifarious :  in    four  vertical  ranks. 

Quddnfid :  four-cleft. 

Quadr [foliate :  four-leaved. 

Quadrifoliolate  :  of  four  leaflets. 

Quadrijugate :  four-paired. 

Quadripartite :  four-parted. 

Quandang-nuts,  460. 

Quassia,  405. 

Quaternary  :  consisting  of  four,  239. 

Quaternary  products,  53,  57,  196. 

Quate'rnate:  in  fours. 

Quercitron,  Quercine,  476. 

Quin-,   in   Latin   compounds :   five   in 

number. 
Quinary  :  consisting  of  five,  234,  239. 
Quinate :  in  fives. 
Quince,  416. 
Quincuncial:  five-ranked;  in  a  quincunx, 

135,  270. 
Quinine,  Quinia,  57,  433. 
Quinquefarious :  five-ranked. 
Quinquefoliate :  five-leaved. 
Quinquefdliolate :  of  five  leaflets. 
Quinquelocular :  five-celled. 
Quinquina  Bark,  433. 
Quintuple  :  dividing  into  five  parts. 
Quintuple-ribbed,  or 
Quintupli-nerved,  156. 

Race:  a  variety  perpetuable  by  seed, 
356. 

Raceme :  an  indefinite  inflorescence  with 
single  pedicelled  flowers  arranged 
along  a  prolonged  axis;  211,  fig. 
307. 

Racemiferous :  bearing  racemes. 

Race'miform:  resembling  a  raceme. 

Racemose :  bearing  or  resembling  ra- 
cemes. 

Rachis :  see  Rhachis. 

Radial :  belonging  to  the  border  or  ray. 

Radiate,  radiant :  spreading  from  or 
arranged  around  a  centre ;  having 
rays. 

Rddiated-veined,  156. 

Radical:  relating  to  the  root  (radix). 

Radical  leaves :  those  apparently  spring- 
ing from  the  root,  143. 

Rddicant:  rooting. 

Radicel:  a  diminutive  root  or  rootlet. 

Radicifldrous :  flowering  from  the  root, 
or  apparently  so. 

Radiciform :  appearing  like  a  root. 

Radicle :  a  diminutive  root ;  the  part  of 


an  embryo  below  the  cotyledons, 

71,  324. 
Radii:  rays. 
Rafflesiaceoe,  463. 
Ramal,  or  rameal :  relating  to  branches, 

143. 
Rame'nta,  raments :  thin  chaffy  scales  in 

place  of  hairs. 
Ramentdceous :  bearing  raments,  as  the 

stalks  of  many  Ferns. 
Ramification,  97. 

Rdmijlorous :  flowering  on  the  brandies. 
Ramose:     bearing    branches    (rami)  ; 

branchy.* 
Rdmulose :    bearing    many    branchlets 

(rdmuli). 
Ranunculaceae,  380. 
Raphe :  see  Rhaphe. 
Raphides  :  crystals  in  plants,  59 
Rare :  thinly  set ;  sparse  or  few. 
Raspberry,  416. 
Ray :  the  marginal  flowers  of  a  head, 

when  different  from  the  rest,  436  ; 

the  branches  of  an  umbel,  &c. 
Ray -flower,  436. 

Receptacle  of  the  flower,  224,  266. 
Receptacle  of  inflorescence,  211,  215. 
Recess:  same  as  sinus. 
Re'clinate,   reclined:    falling  or  turned 

downwards. 
Re'clinerved :  parallel-veined. 
Rectiserial:  in  rectilinear  ranks,  141. 
Recurved:     curved,   especially    curved 

backwards. 
Reduplicate,  reduplicative,  273. 
Refle'xed :   bent   downwards   or   back- 
wards. 
Refracted:  suddenly  bent  backwards. 
Regular :  the  members  alike  in  size  and 

form,  239,  277. 
Reniform:    kidney-shaped  ;     same    as 

round-heart-shaped,  but  the  breadth 

greater  than  the  length  ;  fig.  245. 
Repdnd:  bowed,  the  margin  obscurely 

sinuate,  159,  fig.  257. 
Repent:  same  as  creeping,  102. 
Replicate :  folded  back. 
Re'plum   (a  door-case)  ;  the  frame-like 

placenta?  of  Papaveracese,  &c.  from 

which  the  valves  of  the  pod  fall 

away  in  dehiscence. 
Reproduction,  20, 21,  61 ; — in  Cryptoga- 

mous  plants,  330. 
Reproductive  organs,  70. 
Reptant :  same  as  repent. 
Resedacese,  391. 
Resins,  195. 

Respiration,  178, 199,  202. 
Restiacese,  496. 
Resiipinate :  underside  up,  or  having  that 

appearance. 
Reticulated:  netted,  154. 


GLOSSARY   AND    INDEX. 


547 


Reticulated  ducts,  46. 

Retinaculum  :  a  stay  or  holdfast :  ap- 
plied to  the  processes  bearing  the 
seeds  of  Acanthaceas,  &c. 

Re'tinerved :  same  as  reticulated. 

Retroairved :  same  as  recurved. 

Retrofle'xed :  same  as  reflexcd. 

Retrofracted :  same  as  refracted. 

Retrorse :  backwards,  directed  back- 
wards. 

Retrove'rted :  turned  upside  down. 

Refuse :  slightly  notched  at  a  rounded 
apex;  162,  fig.  272. 

Re'volute,  resolutive :  rolled  backwards, 
144. 

Rhachis  (back-bone)  :  the  axis  of  a 
spike,  &c,  211. 

Rhamnaeea?,  408. 

Rhaphe  of  an  ovule  or  seed,  299,  fig. 
529,  r. 

Rhatany,  412. 

Rhizdnthous :  root-flowered;  as  when  a 
flower  (like  Raffiesia,  fig.  150),  or 
a  cluster  of  flowers,  &c.  without 
green  foliage  (like  Beech-drops), 
is  parasitic  by  what  answers  to 
roots,  on  some  foster  plant. 

Rhizocdrpous  (root-fruiting)  :  having  a 
perennial  root. 

Rhizdma:  rootstock,  106. 

Rhizomorphous :  root-like. 

Rhizophoraceas,  419. 

Rhodospermeas,  509. 

Rhombic :  rhomb-shaped. 

Rhomboidal :  approaching  a  rhomboid 
in  form. 

Rhubarb,  466. 

Rib :  a  strong  nerve  or  part  of  the  frame- 
work of  a  leaf,  &c,  145,  155. 

Ribbed:  when  strong  nerves  or  ribs  run 
lengthwise  through  a  leaf,  &c. 

Ricciacese,  504. 

Rice,  498. 

Rimose:  with  chinks  or  clefts  (rimce). 

Ring  of  Ferns,  501 ;  of  Mosses,  503. 

Ringent :  grinning ;  when  a  bilabiate 
corolla  is  open,  278. 

Riparious :  along  water-courses. 

Root,  79. 

Root-hairs,  81. 

Rootlet :  a  very  small  root,  or  ultimate 
branch  of  a  root. 

Rootstock :  same  as  rhizoma,  106. 

Rosacea?,  415. 

Rosaceous :    rose-like,  276. 

Rdstellate :  diminutive  of  rostrate. 

Rosteilum :  a  little  beak. 

Rdstrate :  beaked,  bearing  a 

Rostrum  :  a  beak-like  projection. 

Rdsular,  or  rosulate :  shaped  like  a  ro- 
sette. 

Rotate :  wheel-shaped  ;  278,  fig.  454. 


Rotation  in  cells  :  see  Cyclosis,  31. 

Rotund,  rotundate :  of  rounded  outline. 

Rough :  see  Scabrid  or  Scabrous. 

Rubescent,  rubicund :  reddish  or  rosy. 

Rubiaceoe,  431. 

Rubiginose :  rusty  reddish. 

Ruderal :  growing  in  rubbish. 

Rudimentary :  imperfectly  or  incom- 
pletely developed. 

Rufescent :  approaching  to 

Rufous :  brown-red. 

Rugose:  wrinkled  (ruga,  a  wrinkle). 

Ruminated  (albumen)  :  penetrated  with 
holes  or  channels ;  323,  383,  fig. 
658. 

Runcinate :  saw-toothed,  the  teeth  turned 
backwards,  161,  fig.  279. 

Runner,  102. 

Running,  102. 

Rupestrine :  growing  naturally  on  rocks. 

Ruptile :  bursting  irregularly. 

Rusty:  see  Ferrugineous. 

Rutacea;,  405. 

Rye,  498. 

Sdbuline,  or  sdbulose :  growing  in  sand. 

Saccate,  sacciform :  sac-shaped,  278. 

Sac  of  the  amnios,  304. 

Saffron,  491,  437. 

Sagittate :  arrow-headed,  or  arrow- 
shaped  ;  lanceolate  with  a  lobe  a$ 
the  base  on  each  side  pointing 
backwards  ;  fig.  252. 

Sago,  481,  485. 

Salep,  489. 

Salicaceae,  or  Salicinia?,  478. 

Salicine,  478. 

Saline,  salsuginous :  growing  in  salt 
places,  or  impregnated  with  salt. 

Salver-shaped:  tubular  and  the  border 
spreading  flat  at  right  angles  to  the 
tube  ;  277,  fig.  457. 

Salviniea?,  502. 

Samara :  a  key  or  winged  indehiscent 
fruit,  314,  fig.  577,  578. 

Sdmaroid:  resembling  a  samara. 

Sambuceas,  431. 

Sandal-wood,  414,  469. 

Santalaceai,  468. 

Sap,  53,  190. 

Sapindacece,  409. 

Sap-green,  408. 

Sapodilla  Plum,  443. 

Sapotaceoe,  443. 

Sap-wood,  35,  124,  126. 

Sdrcocarp :  the  fleshy  part  of  a  drupe, 
310,  312. 

Sarmentdceous :  bearing  or  resembling 

Sarments :  runners  or  long  and  flexible 
branches. 

Sarraceniacese,  387. 

Sarsaparilla,  493. 


548 


GLOSSARY   AND    INDEX. 


Saururaceas,  469. 

Saw-toothed:  same  as  Serrate. 

Sdxatile :  living  in  rocky  places. 

Saxifragacea;,  424. 

Scabrate,  scabrid,  or  scabrous :  rough  to 

the  touch. 
Scaldriform :  ladder-shaped,  or  barred. 
Scalariform  ducts,  46. 
Scales :  any  thin  scale-like  appendages ; 

usually  degenerated  leaves,  105. 
Scalloped:  same  as  Crenate. 
Scaly :  furnished  with  scales,  95,  191. 
Scammony,  455. 
Scandent :  climbing. 
Scape:  a  flower-stalk  rising  from  the 

ground  or  near  it,  220. 
Scdpiform,  or  scapoid :    resembling  a 

scape. 
.Scar :  see  Leaf-scar  and  Hilum. 
Scdriose,  or   scdrious :     thin,    dry,    and 

membranaceous. 
Scattered :  either  sparse,  or  without  ap- 
parent symmetry  of  arrangement. 
Schizandreae,  382. 
Scion :  a  shoot,  especially  one  used  for 

grafting. 
Sciuroid:  like  a  squirrel's  tail. 
Sclerantheaj,  396. 
Scle'roqen  :  same  as  Lignine,  36. 
Scobiform,  or  scobicular:  like  sawdust. 
Scorpioid :  coiled  round  like  a  scorpion, 

as   the  branches  of  the  cyme  of 

Heliotrope. 
Scrobiculate :  pitted. 
Scrophulariacece,  448. 
Scrdtiform :  pouch-shaped. 
Scurf:  minute   or  bran-like  scales   on 

the  epidermis,  52. 
Scutate,  scutiform  :  shield-shaped. 
Scute'lliform  :  shaped  like  a  platter  (scu- 

tella). 
Secretions,  51. 

Sectile :  divided  into  portions. 
Secund :  all  turned  to  one  side  of  an 

axis. 
Secundine :  the  second  coat  of  an  ovule, 

298. 
Seed,  70,  320. 
Seed-vessel,  308. 
Segment :  one  of  the  divisions  or  lobes 

of  a  leaf  or  other  organ ;  159,  275. 
Segregate :  kept  separate. 
Semi-,  in  Latin  compounds  :  half. 
Semi-adherent :  the  lower  half  adherent. 
Semi-amplexicaul :  half-clasping. 
Semicordate:  hah0 heart-shaped  (divided 

lengthwise). 
Semi-double :  half-double. 
Semi-floscular :  when  the  flowers  of  a 

head  are  ligulate. 
Semilunar,  or  semilunate :  like  a  crescent 

or  half-moon. 


Seminal :  relating  or  belonging  to  the 

seed. 
Seminiferous :  seed-bearing. 
Semiorbicular :  half-round. 
Semioval :  half  of  an  oval,  and 
Semiovate :  half  of  an  ovate  figure,  di- 
vided longitudinally. 
Semisagittate  :  arrow-headed   with   one 

lobe  wanting. 
Semiseptate :  a  partition  reaching  partly 

across. 
Semiterete :  half-cylindrical. 
Sempervirent :  evergreen. 
Senna,  414. 
Sensitive  plants,  345. 
Sepal:  a  calyx-leaf,  222. 
Se'paline,  sepalous :   relating  to  sepals. 
Se'paloid :  resembling  a  sepal. 
Separated  flowers :  the  stamens  and  the 
pistils  occupying  separate  blossoms, 
261. 
Septate:  with  a  partition  (septum). 
Septicidal,     or     se'pticide :      dehiscent 
through  the  partitions,  i.  e.  by  the 
lines   of  junction;    316,  fig.   582, 
584. 
Septiferous :  bearing  a  partition. 
Septifragal :  where  the  valves  separate 

from  the  dissepiments,  317. 
Septum   (plural  septa)  :    a  partition  of 

any  kind,  316. 
Se'rial,  or  striate :  arranged  in  rows. 
Sericeous :  silky. 
Series:  rank. 

Serotinous :  flowering  or  fruiting  late. 
Serrate:  beset  with  teeth  pointing  for- 
wards, like  those  of  a  saw,  159,  fig. 
254. 
Serratures :  the  teeth  of  a  serrate  body. 
Serrulate :  serrate  with  fine  teeth. 
Sesameae,  447. 
Sdssile  (sitting)  :  not  stalked,  145,  211, 

281. 
Seta :  a  bristle,  or  bristle-like  body,  52. 
Setaceous,  setiform :  like  a  bristle. 
Setigerous :  bristle-bearing. 
Setose :  bearing  or  abounding  with  bris- 
tles. 
Se'tula :  diminutive  of  Seta. 
Se'tulose :  bearing  minute  bristles. 
Sex :  six ;  as  in 
Sexangular :  six-angled. 
Sexfarious :  six-rowed. 
Sexpartite :  six-parted,  &c. 
Shaggy :  see  Villous. 
Sheath :  a  tubular  body,  enclosing  or 
surrounding  some   other ;    as  the 
base  of  the  leaves  of  Grasses  ;   1 7G, 
fig.  237. 
Sheathing :  forming  a  sheath  ;  see  Va- 

ginate. 
Shields :  see  Apothecia,  506. 


GLOSSARY   AND    INDEX. 


549 


Shield-shaped:  see  Peltate,  158,  fig.  248, 
681. 

Shoot :  any  fresh  branch. 

Shrub,  shrubby,  101. 

Sigillate :  as  if  marked  with  the  impres- 
sion of  a  seal,  as  in  Solomon's  Seal, 
fig.  168. 

Sigmoid :  curved  like  the  Greek  sigma, 
or  letter  S. 

Signs  used  in  Botany,  517. 

Sileneas,  395. 

Silicle :  a  pouch,  or  short  pod  of  Cru- 
ciferaj,  317,  fig.  703. 

Siliculosa,  515. 

Siliculose:  having  or  resembling  a  sili- 
cle. 

Silique :  a  long  pod  of  Cruciferae  ;  317, 
fig.  589. 

Siliquosa,  516. 

Siliquose:  like  a  silique. 

Silk-cotton,  399. 

Silky :  clothed  with  fine,  appressed,  and 
glossy  hairs,  producing  a  satiny 
surface. 

Silver-berry,  468. 

Silver-grain,  120. 

Simarubacese,  405. 

Simple :  of  one  piece  or  rank. 

Simple  fruits,  309,  311;  leaves,  162; 
pistil,  288. 

Sinistrdrse :  turned  to  the  left. 

Sinuate :  strongly  wavy  on  the  margin, 
with  alternate  convexities  and  con- 
cavities ;  159,  fig.  258. 

Sinus  :  a  re-entering  angle  or  recess. 

Slashed :  same  as  Laciniate. 

Sleep  of  plants,  344. 

Smilaceas,  492. 

Smooth  :  not  pubescent  or  hairy,  or  else 
(and  more  strictly)  not  rough. 

Snake-root,  412,  462. 

Soap-berry,  410. 

Soboliferous  :  bearing  shoots  (sobofes). 

Social  (plants) :  growing  gregariously. 

Solanacese,  456. 

Solitary :  single  ;  alone. 

Soluble :  separating  into  parts. 

Sore'diate :  bearing  little  patches  on  the 
surface. 

Sorose :  heaped,  or  bearing. 

Sorosis :  a  fleshy  multiple  fruit,  like  a 
mulberry. 

Sori  (sing,  sorus) :  heaps  or  patches,  as 
those  of  the  spore-cases  of  most 
Ferns,  called  in  English  fruit-dots, 
501. 

Spadiceous :  bearing  a 

Spadix :  a  sort  of  flesby  spike,  213. 

Span :  the  length  spanned  between  the 
thumb  and  little  finger ;  seven  or 
eight  inches. 

Sparse :  scattered  and  generally  scanty. 


Spathdceous  :  bearing  a 

Spathe :  the  enveloping  bract  of  a  spa- 
dix, 213. 

Spdthulate,  or  spatulate:  shaped  like  a 
druggist's  spatula. 

Special  directions,  341. 

Species,  19,  354. 

Specific :  relating  to  species. 

Spe~rmaphore :  a  name  for  the  placenta, 
or  the  funiculus  of  the  seed. 

Spermatozoids,  334. 

Spermic,  or  spermous :  relating  to  the 
seed. 

Spe'rmoderm  :  the  outer  seed-coat,  320. 

Spicate:  relating  to  or  disposed  in  a 
spike. 

Spiciform :  spike-like. 

Spicula :  a  spikelet. 

Spike:  a  prolonged  indefinite  inflo- 
rescence with  sessile  flowers,  212. 

Spikelet:  a  diminutive  or  secondary 
spike ;  the  ultimate  flower-clusters 
of  Grasses. 

Spikenard,  435. 

Spindle-shaped,  84,  fig.  138. 

Spine,  104,  167. 

Spinescent:  tipped  with  a  spine,  104. 

Spinose:  spiny,  104. 

Spinidose:  bearing  diminutive  spines. 

Spiral :  as  if  wound  round  an  axis. 

Spiral  arrangement  of  leaves,  134. 

Spiral  markings  on  cells,  39. 

Spiral  vessels  or  ducts,  46. 

Spireae,  416. 

Spithamceous :  a  span  high. 

Spongioles,  or  spongelets,  80. 

Spongy :  of  the  texture  of  sponge. 

Spontaneous  movements,  340,  347. 

Sporadic :  widely  dispersed. 

Sporangium  :  a  spore-case,  337,  500,  &c. 

Spore:  the  body  in  Cryptogamous 
plants  which  answers  to  the  seed  in 
the  Phajnogamous,  61,  70,  331. 

Spore-case,  337. 

Sporiferous :  spore-bearing. 

Spdrocarp :  a  kind  of  sporangium,  502. 

Sports,  356. 

Spdrule :  a  spore,  or  small  spore. 

Sporulifcrous :  bearing  sporules. 

Spumescent,  spumose :  froth-like. 

Spur:  any  tubular  projection,  278. 

Spurred:  bearing  a  spur,  278. 

Spiamate,  squamose,  squamiferous  :  fur- 
nished with  scales  (squamce). 

Squdmellate :  with  or  resembling  minute 
and  narrow  scales  (squamelloz,  497). 

Squdmiform :  scale-shaped. 

Squdmidiform  :  like  a  small  scale,  or 

Squdmula,  497. 

Squdmulose  :  covered  with  small  scales. 

Squairose:  where  scales,  small  leaves, 
or  other  bodies,  spread  widely  from 


550 


GLOSSARY    AND    INDEX. 


the  axis  on  which  they  are 
crowded. 

Squdrrulose :  diminutive  of  Squarrose. 

Squash,  423. 

Squills,  493. 

Stalked :  furnished  with  a  stalk,  stem, 
or  any  lengthened  support. 

Stalked  (/lands,  52. 

Stalklet:  a  diminutive  or  secondary 
stalk. 

Stamen :  the  fertilizing  organ  of  a  flow- 
er, 223. 

Stdminate,  or  stamineal:  relating  to  the 
stamens.  A  staminate  flower  has 
no  pistils,  261. 

Staminiferous :  bearing  stamens. 

Staminddium:  an  altered  and  sterile  sta- 
men, or  a  body  occupying  the  place 
of  a  stamen. 

Standard:  the  posterior  petal  of  a  pa- 
pilionaceous corolla,  253. 

Staphyleacece,  409. 

Star-apple,  443 . 

Starch,  54,  193. 

Staticese,  445. 

Station:  the  locality  or  kind  of  situa- 
tion in  which  a  nlant  naturally 
grows. 

Stellatae,  432. 

Stellate:  starry,  star-shaped;  arranged 
in  rays,  like  the  points  of  a  star. 

Stellate  hairs,  52. 

Ste'llulate :  diminutive  of  Stellate. 

Stem,  91. 

Stemless :  having  no  obvious  stem,  91. 

Slemlet :  a  diminutive  stem ;  the  first 
internode  of  the  plumule. 

Sterculiacere,  399. 

Sterigma :  the  adherent  base  or  down- 
ward prolongation  of  a  decurrent 
leaf. 

Sterile:  barren. 

Sterile  flower :  one  having  no  pistils, 
261. 

Sterile  stamens  or  Jllaments :  those  des- 
titute of  anthers,  or  with  the  anther 
imperfect,  281. 

Stigma :  the  part  of  a  pistil  which  re- 
ceives the  pollen,  223,  287. 

Stigmdtic,  or  stigmatose :  relating  to  or 
bearing  the  stigma. 

Stings,  stinging  hairs,  52. 

Stipe  (stipes) :  a  stalk  of  an  ovary  (267), 
of  a  Mushroom  (507),  and  the 
leaf-stalk  of  a  Fern. 

Slipel :  the  stipule  of  a  leaflet ;  1 7 1 ,  fig. 
286. 

Stipellate:  furnished  with  stipels,  171. 

Stipitate:  having   a  stipe,  267. 

Stipitiform  :  shaped  like  a  stipe. 

Stipiddceous,  stipular :  belonging  to  or 
resembling  stipules. 


Stipulate,  stipuled:   possessing   stipules, 

171. 
Stipule:  an   accessory   part  of  a  leaf, 

one  on  each  side  of  the  base,  145, 

170. 
Stock,  355. 

Stole,  stolon:  a  rooting  branch,  102. 
Stoloniferous :  bearing  stolons. 
Stoma    (plural     stdmata),    stomate:    a 

breathing-pore,  52, 150. 
Stomatiferous :  bearing  stomates. 
Stone :  the  endocarp  of  a  drupe. 
Stone-fruit,  312. 
Stool :  the  plant  from  which  layers  arc 

propagated. 
Storax,  425,  442. 
Stramineous :  straw-like. 
Strangulated :  irregularly  contracted. 
Strap-shaped:  see  Ligulate. 
Stratum :  a  layer. 
Strawberry,  416. 
Striate :    marked     with     longitudinal 

streaks  or  furrows  (strioz). 
Strict :  very  straight  or  close,  or  very 

upright. 
Strigillose  :  same  as  Strigose. 
Strigose :    clothed  with  sharp  and  stout 

close-pressed    hairs    or    scale-like 

bristles  (strigce). 
Strobildceous :   relating    to,    or    resem- 
bling a 
Strdbile  :  the  cone  of  a  Pine,  &c.,  319. 
Strobiliferous :  bearing  strobiles. 
Strombuliferous :  spirally  twisted,  like  a 

corkscrew  or  a  strombus. 
Strdphiole :  same  as  a  Caruncle,  322. 
Structural  Botany,  14. 
Strumose :  swollen  on  one  side,  bearing 

a  struma  or  wen. 
Strychnine,  57,  434. 
Stupose:  tow-like. 
Style :  a  columnar  or  slender  part  of  the 

pistil  above  the  ovary,  223,  287. 
Styliferous :  style-bearing. 
Styliform :  style-shaped. 
Stylopddium :    an  enlargement  or  fleshy 

disk  at  the  base  of  a  style,  as  in 

Umbelliferse. 
Styraceas,  442. 
Sub-,  as  a  prefix,  means  somewhat,  or 

slightly ;  as 
Subacute :  somewhat  acute. 
Subclass,  362. 

Subcordate  ;  slightly  heart-shaped,  &c. 
Siiberose :  of  a  corky  texture. 
Subgenus,  361,  362. 
Submerged :  growing  under  water. 
Suborder,  361. 

Subspecies  :  a  marked  variety. 
Subtribe,  361. 

Subterranean  :  growing  beneath  the  sur- 
face of  the  ground. 


GLOSSARY   AND    INDEX. 


551 


Subulate,  subidiform :  awl-shaped  ;  nar- 
row, and  tapering  to  a  sharp  rigid 
point,  as  the  leaves  of  Juniper,  &e. 
166. 

Succise :  as  if  cut  off  at  the  end. 

Succose,  succulent:  juicy. 

Siiccubous:  the  apex  of  each  leaf  cov- 
ered by  the  base  of  the  next,  as  in 
Jungermannia. 

Succulent  leaves,  166. 

Sucker,  102. 

Suffrute'scent :  slightly  shrubby,  101. 

Suffnitex :  an  undershrub. 

Suffriiticose:  low  and  shrubby,  or  shrub- 
by at  the  base,  101. 

Sugar,  53,  193,  194. 

Sulcate :  longitudinally  grooved. 

Supe>--,  above ;  as 

Super<ixillai-y :  above  the  axil. 

Superior:  above,  252  ;  also,  on  the  up- 
per side  of  the  flower,  i.  e.  next  the 
common  axis  (237),  as,  for  exam- 
ple, the  vexillum  of  a  papiliona- 
ceous corolla  (fig.  372,  a)  is  the 
superior  petal. 

Superposed :  one  above  another. 

Superposition,  248. 

Supe'rvolute,  274. 

Supine:  lying  flat  with  face  upwards. 

Suppi-ession :  obliteration  of  parts,  239, 
255. 

Supra-,  above  ;  as 

Supra-axillary  :  above  the  axil. 

Supra-decompound:  several  times  com- 
pounded. 

Siirculose :  producing  suckers. 

Siirculus  :  a  sucker,  102. 

Suspended:  hanging  from  the  apex,  297. 

Suspensor  of  the  embryo,  306. 

Sutural :  relating  to  the 

Suture:  the  seam,  or  line  of  opening 
of  a  pod,  &c,  289. 

Sword-shaped:  a  blade  with  two  sharp 
and  nearly  parallel  edges,  tapering 
to  a  point,  as  in  Iris,  fig.  291. 

Syconium,  or  syconus:  such  a  fruit  as  a 

fig-  . 
Symmetrical :    equal  in  the  number  of 

all  the  parts,  232,  239. 
Sympetalous :  becoming  somewhat  mon- 

opetalous  by  a  junction  of  the  base 

of  the  petals  with  the  monadel- 

phous  stamens,  as  in  the  Mallow 

family. 
Symphydntherous :  same  as  Syngenesious. 
Symphysis :  a  growing  together  of  parts. 
Symphyste'monous  :  the  stamens  united. 
Symplocinese,  443. 
Syndntherous :  united  by  their  anthers; 

whence    Compositae     have    been 

named 
Synantheroe,  435. 


Syncdrpous  :    formed  of  two   or  more 

united  carpels,  290. 
Syncotyledonous :  the  cotyledons  soldered 

together. 
Synedral:  growing  on  the  angles. 
Syne'ma :  a  name  for  a  column  of  mon- 

adelphous  filaments. 
Syngenesia,  513. 
Syngenesious :  stamens  united  by  their 

anthers  ;  280,  fig.  463. 
Synonyme:    equivalent   or    superseded 

names. 
Synonymy :  what  relates  to  synonymes. 
System,  365,  366. 
Systematic  Botany,  15,  351. 

Tabescent :  wasting  or  shrivelling. 

Tabular :  flattened  horizontally. 

Tail :  any  long  and  slender  terminal 
appendage. 

Tail-pointed :  tipped  with  a  prolonged 
and  weak  acumination. 

Tannin,  Tannic  Acid,  57. 

Taper-pointed:  same  as  Acuminate. 

Tapioca,  472. 

Tap-root,  84. 

Tar,  480. 

Taro,  485. 

Tawny:  dull  yellowish,  verging  to 
brown. 

Taxineaj,  480. 

Taxology,  or  Taxdnomy :  the  depart- 
ment of  Botany  which  relates  to 
classification. 

Tea,  401. 

Teasels,  435. 

Teeth  of  calyx,  corolla,  &c.,  275  ;  of 
leaves,  159. 

Teqmen:  the  inner  seed-coat,  321. 

Tendril,  102,  167. 

Tepal :  a  name  proposed  for  a  leaf  or 
part  of  the  perianth  when  it  is  un- 
certain whether  it  belongs  to  the 
calyx  or  the  corolla. 

Teratology :  morphology  applied  to 
monstrous  states. 

Tercine :  a  third  coat  of  the  ovule. 

Terete :  long  and  round,  i.  e.  the  cross- 
section  circular. 

Tergeminate :  thrice  twin. 

Te'rminal:  belonging  or  relating  to  the 
summit. 

Terminology:  the  same  as  Glossologv, 
15. 

Ternary:  consisting  of  three,  239. 

Ternary  products,  53. 

Ternate:  in  threes. 

Temstreemiaceae,  401. 

Tessellated:  in  checker- work. 

Testa:  the  outer  seed-coat,  320. 

Testaceous :  brownish-yellow,  like  un- 
jrlazed  earthen-ware. 


552 


GLOSSARY   AND    INDEX. 


Trtra-,  in  Greek  compound  words :  four. 

Tetracdrpellary :  of  four  carpels. 

Tetracdmarous :  same  as 

Telracdccous :  of  four  cocci. 

Tctradynamia,  512. 

Tetradynamous :  two  of  the  six  stamens 
shorter  than  the  rest ;  281,  fig. 
407. 

Tetragonal,  or  tetrdgonous :  four-angled. 

Tetragynia,  515. 

Tetrdgynous :  with  four  pistils  or  styles, 
287. 

Tetrdmerous :  the  parts  in  fours,  234, 
239. 

Tetrandria,  512. 

Tetrdndrous :  with  four  stamens,  279. 

Tetrape'talous :  with  four  petals,  276. 

Tetraphyllous :  foui'-leaved,  275. 

Tetraque'trous :  quadrangular,  with  very 
sharp  and  salient  angles. 

Tetrase'pahus :  with  four  sepals,  274. 

Tetrdstichous :  with  four  vertical  ranks. 

Tludamijldrous  :  with  the  stamens,  &c. 
inserted  in  the  receptacle,  or 

Thalamus :  the  receptacle  of  a  flower. 

Thallophytes,  371,  505. 

Tlmllus,  67,  371,  505. 

T/teca:  an  anther-cell,  281 ;  or  a  spore- 
case,  499,  500. 

Thecaphore :  same  as  Gynophore,  267. 

Thread-shaped :  see  Filiform,  166. 

Throat :  the  orifice  of  a  tubular  organ, 
275,  276. 

Thorn,  104. 

Thijrse,  or  thyrsus:  a  thick  panicle,  217. 

Thyrsoid:  like  a  thyrse. 

Thvmelacea?,  467 

Tieute,  434. 

TiliaceEe,  399. 

Tissue:  the  fabric  of  plants,  22. 

Tobacco,  456. 

Tomato,  456. 

Tomentose :  clothed  with 

Tome'ntum :  a  close  and  matted  down  or 
wool. 

Tongue-shaped :  long,  fleshy,  nearly  flat, 
and  rounded  at  the  end. 

Tonka-bean,  414. 

Tooth :  any  short  and  narrow  projec- 
tion. 

Toothed:  same  as  Dentate  ;  beset  with 
teeth  which  on  the  leaf  do  not  point 
forwards;  159,  fig.  255. 

Top-shaped:  inversely  conical. 

Torose :  a  cylindrical  body  swollen  at  in- 
tervals. 

Tortuous:  bent  in  different  directions. 

Tdrulose :  somewhat  torose. 

Torus:  the  receptacle  of  the  flower, 
224. 

Trabe'culate :  cross-barred. 

Trachea  :  a  spiral  vessel  or  duct,  46. 


Trache'nchyma,  46. 

Trapezoid,  or  Irapeziform :  unsymmet- 
rically  four-sided,  like  a  trape- 
zium. 

Tree,  101. 

Tri-,  in  compound  words  :  three ;  as 

Triade'lphous :  having  the  filaments  in 
three  sets,  280. 

Triandria,  512. 

Tridndrous:  with  three  stamens,  279. 

Triangidar :  three-angled. 

Trianthous :  three-flowered. 

Tribe,  361. 

Tricdrpellary :  of  three  carpels. 

Tricdrpous  :  with  three  ovaries. 

Trice'phalous :  three-headed. 

Trichdtomous  :  branched  into  threes. 

Tricdccous :  of  three  cocci. 

Triaispidate :  three-pointed. 

Tride'ntate :  three-toothed. 

Triennial :  lasting  three  years. 

Tri  furious  :  in  three  vertical  ranks. 

Trffid:  three-cleft ;  159,  fig.  265. 

Trifoliate :  three-leaved. 

Trifdliolate :  of  three  leaflets. 

Tri  furcate:  three-forked. 

Trigamous :  having  three  sorts  of  flowers. 

Trigonal,  or  trigonous :  three-angled. 

Trigynia,  515. 

Trigynous :  with  three  pistils  or  styles, 
287. 

Tri  jugate :  three-paired. 

Trilateral :  three-sided. 

Trilliacea;,  493. 

Trilobate :  three-lobed. 

Trildcular :  three-celled. 

Trimerous :  the  parts  in  threes ;  234, 
239,  fig.  353. 

Trine'rvate :  three-nerved. 

Trinddal:  of  three  nodes  or  joints. 

Tricecia,  516. 

Trieecious,  or  trioicous :  having  stami- 
nate,  pistillate,  and  perfect  flowers 
on  three  different  plants. 

Tridvidate :  having  three  ovules. 

Tripartible :  capable  of  splitting  into 
three. 

Tripartite :  three-parted. 

Tripe'talous :  of  three  petals,  276. 

Triphyllous :  three-leaved,  275. 

Tripinnate:  thrice  pinnate,  164. 

Tripinndtifid :  thrice  pinnatifid,  161. 

Triple-ribbed,  or  nerved:  same  as 

Trip/i-nerved,  155. 

Tripterous:  three-winged. 

Trique'trous  :  with  three  salient  angles. 

Trisepalous :  of  three  sepals,  274. 

Trise'rial,  or  trise'riate :  in  three  horizon- 
tal ranks. 

Tristichous :  in  three  vertical  ranks,  134. 

Tristigmdtic  :  with  three  stigmas. 

Tristylous:  with  three  styles. 


GLOSSARY   AND    INDEX. 


553 


Trisiilcate :  three-grooved. 

Triternate:  thrice  ternate,  164. 

Trivial  name :  the  popular  name ;  or 
the  specific  name. 

Trochlear :  pulley-shaped. 

Tropseolacese,  404. 

Trophosperm :  the  placenta. 

Tropical :  growing  near  or  between  the 
tropics. 

Trumpet-shaped :  tubular,  with  the  sum- 
mit dilated. 

Truncate :  as  if  cut  off  at  the  end ;  162, 
fig.  271. 

Trunk:  a  main  stem. 

Tube:  the  portion  of  a  calyx,  corolla, 
&c.  formed  by  the  union  of  the 
sepals,  petals,  &c,  275. 

Tuber :  a  short  and  thickened  subterra- 
nean branch,  107. 

Tubercle :  a  small  tuber,  or  an  excres- 
cence. 

Tubercled :  bearing  excrescences. 

Tuberiferous :  bearing  tubers. 

Tuberous:  tuber-like  ;  85,  fig.  139. 

Tubulose,  tubular  :  having  a  tube,  or 
tube-shaped,  as  the  corolla  of  Trum- 
pet Honeysuckle,  &c,  277. 

Tubulifloraj,  436. 

Tumid:  somewhat  inflated. 

Tunicate :  having  an  accessory  covering 
(tunic). 

Tunicated  bulb,  109. 

Turbinate :  top-shaped. 

Turio,  turions :  the  early  state  of  a  suck- 
er or  subterranean  shoot,  as  an 
Asparagus-shoot,  95. 

Turmeric,  490. 

Turneracese,  422. 

Turnip-shaped :  see  Napiform,  84. 

Turnsole,  473. 

Turpentine,  57,  480. 

Twin :  in  pans. 

Twining:  winding  spirally  round  a  sup- 
port, 102. 

Two-lipped,  255. 

Type:  the  pattern  or  ideal  plan,  231, 
238. 

Typhacese,  485. 

Typical :  representing  the  type  or  plan. 

Uliginose:  growing  in  marshes. 

Ulmacese,  474. 

Ulmine,  Ulmic  Acid,  57. 

Umbel:  an  umbrella-shaped  inflores- 
cence, 212. 

t  'mbellate,  umbelliform  :  in  umbels. 

Umbellet:  a  secondary  or  partial  um- 
bel, 216. 

Umbellifera,  425. 

Umbelliferous :  bearing  umbels. 

Umbilicate:  depressed  in  the  centre, 
like  the  navel. 

47 


Umbilicus :  the  hilum  of  a  seed  ;  a  cen- 

,      tral  depression. 

Umbonate :  bearing  an  umbo  or  boss, 
a  central  projection. 

Umbrdculiform  :  umbrella-shaped. 

Unarmed:  destitute  of  prickles,  spines, 
&c. 

Uncate:  hooked. 

U'nciform,  or  uncinate :  hooked. 

Undate,  or  undulate  :  wavy. 

Undershrub,  101. 

Unequally  pinnate :  same  as  impari-pin- 
nate,  163. 

Unguicidate :  furnished  with  a  claw  (un- 
guis), as  the  petals  of  Saponaria, 
276,  fig.  449,  &c. 

Uni-,  in  Latin  compounds  :  one. 

Unicellular :  one-celled,  61. 

Unifidrous :  one-flowered. 

Unifdliate :  one-leaved. 

Unifdliolate :  with  one  leaflet. 

Unijugate :  of  only  one  pair,  164. 

Unildbiate:  one-lipped. 

Unilateral :  one-sided :  either  all  dis- 
posed on  one  side  of  an  axis,  or 
turned  to  one  side. 

Unildcular :  one-celled. 

Unine'rvate :  one-nerved. 

Uniovxdate :  one-ovuled. 

Unipe'talous :  having  only  one  petal,  as 
in  Amorpha,  fig.  395. 

Unise'rial,  or  uniseriate:  in  one  horizon- 
tal row  or  whorl. 

Unisexual :  having  stamens  only  or  pis- 

,      tils  only,  261. 

Univalved :  of  one  piece  ;  one-valved. 

Universal :  same  as  General. 

Upas,  475. 

Urceolate :  pitcher-shaped  or  urn-shaped ; 
i.  e.  hollow  and  contracted  at  the 
mouth. 

Urticaceae,  473. 

Utricle  :  a  small  bladdery  fruit,  314. 

Utricular :  bladder-like. 

Utriculariaeete,  or  Utricularinea; :  same 
as  Lentibulacea;,  445. 

Utriculiform  :  shaped  like  a  little  bottle. 

Utriculose :  bearing  utriculi,  or  bladders. 

Uvularieaj,  494. 

Vaccinieae,  or  Vacciniacese,  439. 

Vagina :  the  sheath  of  a  leaf,  &c. 

Vaginant :  sheathing. 

Vaginate :  sheathed. 

Vaginula :  a  little  sheath,  as  that  around 

the  sporangium  of  Peat  Moss. 
Vaginulate  :  with  a  vaginula. 
Vague  :  in  no  definite  order  or  direction. 
Valerian,  434. 
Valerianacece,  434. 
Valleculce:    the  intervals  between  the 

ridges  of  the  fruit  of  Umbelliferae. 


554 


GLOSSARY   AND    INDEX. 


Valvate    or    valvular  aestivation,    &c. : 

where  the  parts  meet  by  their  edges 

without  overlapping,  144,  273. 
Valve :  a  door,  or  portion  into  which  a 

pod,  &c.  separates  in  dehiscence ; 

also  a  piece  or  leaf  of  a  spathe,  &c. 
Valved :  opening  by  valves. 
Vanilla,  489. 
Variegated:  having  one  or  two  colors 

disposed  in  patches. 
Varieties,  355. 
Vascular  :  relating  to  or  furnished  with 

vessels. 
Vascular  Plants,  68. 
Vascular  or  vasiform  tissue,  40,  45. 
Vasculum  :  same  as  Ascidium. 
Vegetable  Ivory,  484. 
Vegetable  Physiology  and   Anatomy, 

14. 
Veil:  see  Calyptra. 
Veined :  furnished  with  slender  vascular 

or  woody  bundles,  especially  with 

branching  ones,  or 
Veins,  145,  155. 

Veinless :  destitute  of  apparent  veins. 
Veinlets :  the  smaller  ramifications  of 

veins,  155. 
Velate:  veiled. 
Velutinous :  velvety  ;  covered  witli  very 

fine  and  close  soft  hairs,  so  that 

the  surface  resembles  velvet  to  the 

touch. 
Venation :  the  mode  of  veining,  1 54. 
Venose :  veiny ;  abounding  in  veins. 
Ventral :  relating  to  the  inner  side  of  a 

simple   pistil,   viz.    that  next    the 

axis. 
Ventral  suture :  the  inner  suture,  289. 
Ve'ntricose :  big-bellied  ;  swelling  out. 
Venlriculose :  somewhat  ventricose. 
Ve'nulose:  abounding  in  veinlets. 
Veratria,  494. 
Verbenaceae,  449. 

Vermicular :  worm-like,  in  shape  or  ap- 
pearance. 
Vernal :  belonging  to  spring. 
Vernation :  the  disposition  of  leaves  in 

the  bud,  143. 
Ve'rnicose :  varnished. 
Ve'rrucose :  warty. 

Verruculose:  studded  with  little  warts. 
Ve'rsatile :  swinging  to  and  fro ;    282, 

fig.  471. 
Vertex :  the  summit. 
Vertical :  perpendicular,  lengthwise. 
Vertical  leaves,  165. 
Vertical  tissue  or  system,  45,  50,  112. 
Verticil,  or  verticel :  a  whorl,  92,  134. 
Verticilldster :  the  pair  of  dense  cymes 

forming    an    apparent  verticil  in 

most  Labiatse,  221. 
Verticillate :  whorled,  133,  142,  221. 


Vesicle :  a  little  bladder. 

Vesicular :  as  if  composed  of  little  blad- 
ders. 

Vespertine :  appearing  or  expanding  in 
the  early  eA'ening. 

Vessels,  40. 

Ve'xillary  aestivation,  271. 

Ve'xillary :  pertaining  to  the 

Vexillum :  the  standard  of  a  papiliona- 
ceous corolla ;  253,  fig.  392,  a. 

Villose,  ox  villous :  shaggy  with  long  and 
soft  hairs,  or  villosity. 

Vimineous:  bearing  or  resembling  long 
and  flexible  twigs,  like  wicker. 

Vine :  any  trailing,  climbing,  or  twining 
stem.  The  Vine,  originally,  is  the 
Grape-vine. 

Violaceae,  or  Violariese,  392. 

Vire'scent :  somewhat  green  (virens). 

Virgate:  twig-like;  wand-like. 

Viridescent:  same  as  Virescent. 

Viscid,  viscous:  sticky  from  a  tena- 
cious secretion. 

Vitacese,  407. 

Vite'llus :  the  thickened  embiyo-sac  per- 
sistent in  the  seed,  as  in  Saururus 
and  Brasenia. 

Viticulose:  producing  small  suckers  or 
stolons  (viticuke). 

llttce  (fillets) :  the  oil-receptacles  of  the 
fruit  of  Umbellifera?,  426. 

Vittate :  bearing  vittae  :  marked  with 
longitudinal  stripes  or  fillets, 
426. 

Viviparous :  germinating  from  the  seed 
(330),  or  sprouting  from  a  bulb, 
&c,  while  still  attached  to  the 
parent  plant. 

Voluble:  twining,  102. 

Volute :  rolled  up. 

Volva :  the  wrapper  of  Fungi,  507. 

Walnut,  476. 

Wavy :  see  Undulate. 

Wax,  56. 

Waxy :  resembling  beeswax  in  appear- 
ance or  consistence. 

Wedge-shaped:  see  Cuneate. 

Wheat,  498. 

Wheel-shaped:  a  corolla  or  calyx  with 
a  veiy  short  tube  and  a  flat- 
spreading  border;  278,  fig.  454. 

Whorl :  a  set  of  organs  arranged  in  a 
circle  round  an  axis,-  92,  134, 
221. 

Whorled:  disposed  in  whorls. 

Whortleberry,  439. 

Wild:  growing  spontaneously. 

Wing:  any  membranous  expansion. 
Also  the  two  side  petals  of  a  pa- 
pilionaceous corolla ;  253,  fig. 
392,  6. 


GLOSSARY   AND    INDEX. 


555 


Winged:  provided  with  wings. 

Winterese  (or  Winteracea:),  381. 

Winter's  Bark,  381. 

Withering :  see  Marcescent. 

Wood,  119. 

Woody  tissue  or  fibre,  40. 

Woolly :  clothed  with  long  and  curling, 

or  matted,  soft  hairs  or  wool. 
Worm-seed,  465. 


Xyridaceae,  496. 

Yam,  492. 

ZanthoxylacCiE,  or  Zanthoxyleas,  406. 
Zingiberacese,  489. 

Zoospores:  free-moving  spores   of  cer- 
tain AlgK  ;  336,  fig.  637,  644. 
Zygophyllaceje,  404. 


THE  END. 


